Merge branch 'multi-coin'

58 files changed, 9508 insertions, 0 deletions

diff --git a/accounts/abi/abi.go b/accounts/abi/abi.go
new file mode 100644
index 0000000..7af6685
--- /dev/null
+++ b/accounts/abi/abi.go
@@ -0,0 +1,192 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+
+	"github.com/ava-labs/go-ethereum/common"
+)
+
+// The ABI holds information about a contract's context and available
+// invokable methods. It will allow you to type check function calls and
+// packs data accordingly.
+type ABI struct {
+	Constructor Method
+	Methods     map[string]Method
+	Events      map[string]Event
+}
+
+// JSON returns a parsed ABI interface and error if it failed.
+func JSON(reader io.Reader) (ABI, error) {
+	dec := json.NewDecoder(reader)
+
+	var abi ABI
+	if err := dec.Decode(&abi); err != nil {
+		return ABI{}, err
+	}
+
+	return abi, nil
+}
+
+// Pack the given method name to conform the ABI. Method call's data
+// will consist of method_id, args0, arg1, ... argN. Method id consists
+// of 4 bytes and arguments are all 32 bytes.
+// Method ids are created from the first 4 bytes of the hash of the
+// methods string signature. (signature = baz(uint32,string32))
+func (abi ABI) Pack(name string, args ...interface{}) ([]byte, error) {
+	// Fetch the ABI of the requested method
+	if name == "" {
+		// constructor
+		arguments, err := abi.Constructor.Inputs.Pack(args...)
+		if err != nil {
+			return nil, err
+		}
+		return arguments, nil
+	}
+	method, exist := abi.Methods[name]
+	if !exist {
+		return nil, fmt.Errorf("method '%s' not found", name)
+	}
+	arguments, err := method.Inputs.Pack(args...)
+	if err != nil {
+		return nil, err
+	}
+	// Pack up the method ID too if not a constructor and return
+	return append(method.ID(), arguments...), nil
+}
+
+// Unpack output in v according to the abi specification
+func (abi ABI) Unpack(v interface{}, name string, data []byte) (err error) {
+	if len(data) == 0 {
+		return fmt.Errorf("abi: unmarshalling empty output")
+	}
+	// since there can't be naming collisions with contracts and events,
+	// we need to decide whether we're calling a method or an event
+	if method, ok := abi.Methods[name]; ok {
+		if len(data)%32 != 0 {
+			return fmt.Errorf("abi: improperly formatted output: %s - Bytes: [%+v]", string(data), data)
+		}
+		return method.Outputs.Unpack(v, data)
+	}
+	if event, ok := abi.Events[name]; ok {
+		return event.Inputs.Unpack(v, data)
+	}
+	return fmt.Errorf("abi: could not locate named method or event")
+}
+
+// UnpackIntoMap unpacks a log into the provided map[string]interface{}
+func (abi ABI) UnpackIntoMap(v map[string]interface{}, name string, data []byte) (err error) {
+	if len(data) == 0 {
+		return fmt.Errorf("abi: unmarshalling empty output")
+	}
+	// since there can't be naming collisions with contracts and events,
+	// we need to decide whether we're calling a method or an event
+	if method, ok := abi.Methods[name]; ok {
+		if len(data)%32 != 0 {
+			return fmt.Errorf("abi: improperly formatted output")
+		}
+		return method.Outputs.UnpackIntoMap(v, data)
+	}
+	if event, ok := abi.Events[name]; ok {
+		return event.Inputs.UnpackIntoMap(v, data)
+	}
+	return fmt.Errorf("abi: could not locate named method or event")
+}
+
+// UnmarshalJSON implements json.Unmarshaler interface
+func (abi *ABI) UnmarshalJSON(data []byte) error {
+	var fields []struct {
+		Type      string
+		Name      string
+		Constant  bool
+		Anonymous bool
+		Inputs    []Argument
+		Outputs   []Argument
+	}
+	if err := json.Unmarshal(data, &fields); err != nil {
+		return err
+	}
+	abi.Methods = make(map[string]Method)
+	abi.Events = make(map[string]Event)
+	for _, field := range fields {
+		switch field.Type {
+		case "constructor":
+			abi.Constructor = Method{
+				Inputs: field.Inputs,
+			}
+		// empty defaults to function according to the abi spec
+		case "function", "":
+			name := field.Name
+			_, ok := abi.Methods[name]
+			for idx := 0; ok; idx++ {
+				name = fmt.Sprintf("%s%d", field.Name, idx)
+				_, ok = abi.Methods[name]
+			}
+			abi.Methods[name] = Method{
+				Name:    name,
+				RawName: field.Name,
+				Const:   field.Constant,
+				Inputs:  field.Inputs,
+				Outputs: field.Outputs,
+			}
+		case "event":
+			name := field.Name
+			_, ok := abi.Events[name]
+			for idx := 0; ok; idx++ {
+				name = fmt.Sprintf("%s%d", field.Name, idx)
+				_, ok = abi.Events[name]
+			}
+			abi.Events[name] = Event{
+				Name:      name,
+				RawName:   field.Name,
+				Anonymous: field.Anonymous,
+				Inputs:    field.Inputs,
+			}
+		}
+	}
+
+	return nil
+}
+
+// MethodById looks up a method by the 4-byte id
+// returns nil if none found
+func (abi *ABI) MethodById(sigdata []byte) (*Method, error) {
+	if len(sigdata) < 4 {
+		return nil, fmt.Errorf("data too short (%d bytes) for abi method lookup", len(sigdata))
+	}
+	for _, method := range abi.Methods {
+		if bytes.Equal(method.ID(), sigdata[:4]) {
+			return &method, nil
+		}
+	}
+	return nil, fmt.Errorf("no method with id: %#x", sigdata[:4])
+}
+
+// EventByID looks an event up by its topic hash in the
+// ABI and returns nil if none found.
+func (abi *ABI) EventByID(topic common.Hash) (*Event, error) {
+	for _, event := range abi.Events {
+		if bytes.Equal(event.ID().Bytes(), topic.Bytes()) {
+			return &event, nil
+		}
+	}
+	return nil, fmt.Errorf("no event with id: %#x", topic.Hex())
+}
diff --git a/accounts/abi/argument.go b/accounts/abi/argument.go
new file mode 100644
index 0000000..4dae586
--- /dev/null
+++ b/accounts/abi/argument.go
@@ -0,0 +1,365 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"encoding/json"
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+// Argument holds the name of the argument and the corresponding type.
+// Types are used when packing and testing arguments.
+type Argument struct {
+	Name    string
+	Type    Type
+	Indexed bool // indexed is only used by events
+}
+
+type Arguments []Argument
+
+type ArgumentMarshaling struct {
+	Name       string
+	Type       string
+	Components []ArgumentMarshaling
+	Indexed    bool
+}
+
+// UnmarshalJSON implements json.Unmarshaler interface
+func (argument *Argument) UnmarshalJSON(data []byte) error {
+	var arg ArgumentMarshaling
+	err := json.Unmarshal(data, &arg)
+	if err != nil {
+		return fmt.Errorf("argument json err: %v", err)
+	}
+
+	argument.Type, err = NewType(arg.Type, arg.Components)
+	if err != nil {
+		return err
+	}
+	argument.Name = arg.Name
+	argument.Indexed = arg.Indexed
+
+	return nil
+}
+
+// LengthNonIndexed returns the number of arguments when not counting 'indexed' ones. Only events
+// can ever have 'indexed' arguments, it should always be false on arguments for method input/output
+func (arguments Arguments) LengthNonIndexed() int {
+	out := 0
+	for _, arg := range arguments {
+		if !arg.Indexed {
+			out++
+		}
+	}
+	return out
+}
+
+// NonIndexed returns the arguments with indexed arguments filtered out
+func (arguments Arguments) NonIndexed() Arguments {
+	var ret []Argument
+	for _, arg := range arguments {
+		if !arg.Indexed {
+			ret = append(ret, arg)
+		}
+	}
+	return ret
+}
+
+// isTuple returns true for non-atomic constructs, like (uint,uint) or uint[]
+func (arguments Arguments) isTuple() bool {
+	return len(arguments) > 1
+}
+
+// Unpack performs the operation hexdata -> Go format
+func (arguments Arguments) Unpack(v interface{}, data []byte) error {
+	// make sure the passed value is arguments pointer
+	if reflect.Ptr != reflect.ValueOf(v).Kind() {
+		return fmt.Errorf("abi: Unpack(non-pointer %T)", v)
+	}
+	marshalledValues, err := arguments.UnpackValues(data)
+	if err != nil {
+		return err
+	}
+	if arguments.isTuple() {
+		return arguments.unpackTuple(v, marshalledValues)
+	}
+	return arguments.unpackAtomic(v, marshalledValues[0])
+}
+
+// UnpackIntoMap performs the operation hexdata -> mapping of argument name to argument value
+func (arguments Arguments) UnpackIntoMap(v map[string]interface{}, data []byte) error {
+	marshalledValues, err := arguments.UnpackValues(data)
+	if err != nil {
+		return err
+	}
+
+	return arguments.unpackIntoMap(v, marshalledValues)
+}
+
+// unpack sets the unmarshalled value to go format.
+// Note the dst here must be settable.
+func unpack(t *Type, dst interface{}, src interface{}) error {
+	var (
+		dstVal = reflect.ValueOf(dst).Elem()
+		srcVal = reflect.ValueOf(src)
+	)
+	tuple, typ := false, t
+	for {
+		if typ.T == SliceTy || typ.T == ArrayTy {
+			typ = typ.Elem
+			continue
+		}
+		tuple = typ.T == TupleTy
+		break
+	}
+	if !tuple {
+		return set(dstVal, srcVal)
+	}
+
+	// Dereferences interface or pointer wrapper
+	dstVal = indirectInterfaceOrPtr(dstVal)
+
+	switch t.T {
+	case TupleTy:
+		if dstVal.Kind() != reflect.Struct {
+			return fmt.Errorf("abi: invalid dst value for unpack, want struct, got %s", dstVal.Kind())
+		}
+		fieldmap, err := mapArgNamesToStructFields(t.TupleRawNames, dstVal)
+		if err != nil {
+			return err
+		}
+		for i, elem := range t.TupleElems {
+			fname := fieldmap[t.TupleRawNames[i]]
+			field := dstVal.FieldByName(fname)
+			if !field.IsValid() {
+				return fmt.Errorf("abi: field %s can't found in the given value", t.TupleRawNames[i])
+			}
+			if err := unpack(elem, field.Addr().Interface(), srcVal.Field(i).Interface()); err != nil {
+				return err
+			}
+		}
+		return nil
+	case SliceTy:
+		if dstVal.Kind() != reflect.Slice {
+			return fmt.Errorf("abi: invalid dst value for unpack, want slice, got %s", dstVal.Kind())
+		}
+		slice := reflect.MakeSlice(dstVal.Type(), srcVal.Len(), srcVal.Len())
+		for i := 0; i < slice.Len(); i++ {
+			if err := unpack(t.Elem, slice.Index(i).Addr().Interface(), srcVal.Index(i).Interface()); err != nil {
+				return err
+			}
+		}
+		dstVal.Set(slice)
+	case ArrayTy:
+		if dstVal.Kind() != reflect.Array {
+			return fmt.Errorf("abi: invalid dst value for unpack, want array, got %s", dstVal.Kind())
+		}
+		array := reflect.New(dstVal.Type()).Elem()
+		for i := 0; i < array.Len(); i++ {
+			if err := unpack(t.Elem, array.Index(i).Addr().Interface(), srcVal.Index(i).Interface()); err != nil {
+				return err
+			}
+		}
+		dstVal.Set(array)
+	}
+	return nil
+}
+
+// unpackIntoMap unpacks marshalledValues into the provided map[string]interface{}
+func (arguments Arguments) unpackIntoMap(v map[string]interface{}, marshalledValues []interface{}) error {
+	// Make sure map is not nil
+	if v == nil {
+		return fmt.Errorf("abi: cannot unpack into a nil map")
+	}
+
+	for i, arg := range arguments.NonIndexed() {
+		v[arg.Name] = marshalledValues[i]
+	}
+	return nil
+}
+
+// unpackAtomic unpacks ( hexdata -> go ) a single value
+func (arguments Arguments) unpackAtomic(v interface{}, marshalledValues interface{}) error {
+	if arguments.LengthNonIndexed() == 0 {
+		return nil
+	}
+	argument := arguments.NonIndexed()[0]
+	elem := reflect.ValueOf(v).Elem()
+
+	if elem.Kind() == reflect.Struct && argument.Type.T != TupleTy {
+		fieldmap, err := mapArgNamesToStructFields([]string{argument.Name}, elem)
+		if err != nil {
+			return err
+		}
+		field := elem.FieldByName(fieldmap[argument.Name])
+		if !field.IsValid() {
+			return fmt.Errorf("abi: field %s can't be found in the given value", argument.Name)
+		}
+		return unpack(&argument.Type, field.Addr().Interface(), marshalledValues)
+	}
+	return unpack(&argument.Type, elem.Addr().Interface(), marshalledValues)
+}
+
+// unpackTuple unpacks ( hexdata -> go ) a batch of values.
+func (arguments Arguments) unpackTuple(v interface{}, marshalledValues []interface{}) error {
+	var (
+		value = reflect.ValueOf(v).Elem()
+		typ   = value.Type()
+		kind  = value.Kind()
+	)
+	if err := requireUnpackKind(value, typ, kind, arguments); err != nil {
+		return err
+	}
+
+	// If the interface is a struct, get of abi->struct_field mapping
+	var abi2struct map[string]string
+	if kind == reflect.Struct {
+		var (
+			argNames []string
+			err      error
+		)
+		for _, arg := range arguments.NonIndexed() {
+			argNames = append(argNames, arg.Name)
+		}
+		abi2struct, err = mapArgNamesToStructFields(argNames, value)
+		if err != nil {
+			return err
+		}
+	}
+	for i, arg := range arguments.NonIndexed() {
+		switch kind {
+		case reflect.Struct:
+			field := value.FieldByName(abi2struct[arg.Name])
+			if !field.IsValid() {
+				return fmt.Errorf("abi: field %s can't be found in the given value", arg.Name)
+			}
+			if err := unpack(&arg.Type, field.Addr().Interface(), marshalledValues[i]); err != nil {
+				return err
+			}
+		case reflect.Slice, reflect.Array:
+			if value.Len() < i {
+				return fmt.Errorf("abi: insufficient number of arguments for unpack, want %d, got %d", len(arguments), value.Len())
+			}
+			v := value.Index(i)
+			if err := requireAssignable(v, reflect.ValueOf(marshalledValues[i])); err != nil {
+				return err
+			}
+			if err := unpack(&arg.Type, v.Addr().Interface(), marshalledValues[i]); err != nil {
+				return err
+			}
+		default:
+			return fmt.Errorf("abi:[2] cannot unmarshal tuple in to %v", typ)
+		}
+	}
+	return nil
+
+}
+
+// UnpackValues can be used to unpack ABI-encoded hexdata according to the ABI-specification,
+// without supplying a struct to unpack into. Instead, this method returns a list containing the
+// values. An atomic argument will be a list with one element.
+func (arguments Arguments) UnpackValues(data []byte) ([]interface{}, error) {
+	retval := make([]interface{}, 0, arguments.LengthNonIndexed())
+	virtualArgs := 0
+	for index, arg := range arguments.NonIndexed() {
+		marshalledValue, err := toGoType((index+virtualArgs)*32, arg.Type, data)
+		if arg.Type.T == ArrayTy && !isDynamicType(arg.Type) {
+			// If we have a static array, like [3]uint256, these are coded as
+			// just like uint256,uint256,uint256.
+			// This means that we need to add two 'virtual' arguments when
+			// we count the index from now on.
+			//
+			// Array values nested multiple levels deep are also encoded inline:
+			// [2][3]uint256: uint256,uint256,uint256,uint256,uint256,uint256
+			//
+			// Calculate the full array size to get the correct offset for the next argument.
+			// Decrement it by 1, as the normal index increment is still applied.
+			virtualArgs += getTypeSize(arg.Type)/32 - 1
+		} else if arg.Type.T == TupleTy && !isDynamicType(arg.Type) {
+			// If we have a static tuple, like (uint256, bool, uint256), these are
+			// coded as just like uint256,bool,uint256
+			virtualArgs += getTypeSize(arg.Type)/32 - 1
+		}
+		if err != nil {
+			return nil, err
+		}
+		retval = append(retval, marshalledValue)
+	}
+	return retval, nil
+}
+
+// PackValues performs the operation Go format -> Hexdata
+// It is the semantic opposite of UnpackValues
+func (arguments Arguments) PackValues(args []interface{}) ([]byte, error) {
+	return arguments.Pack(args...)
+}
+
+// Pack performs the operation Go format -> Hexdata
+func (arguments Arguments) Pack(args ...interface{}) ([]byte, error) {
+	// Make sure arguments match up and pack them
+	abiArgs := arguments
+	if len(args) != len(abiArgs) {
+		return nil, fmt.Errorf("argument count mismatch: %d for %d", len(args), len(abiArgs))
+	}
+	// variable input is the output appended at the end of packed
+	// output. This is used for strings and bytes types input.
+	var variableInput []byte
+
+	// input offset is the bytes offset for packed output
+	inputOffset := 0
+	for _, abiArg := range abiArgs {
+		inputOffset += getTypeSize(abiArg.Type)
+	}
+	var ret []byte
+	for i, a := range args {
+		input := abiArgs[i]
+		// pack the input
+		packed, err := input.Type.pack(reflect.ValueOf(a))
+		if err != nil {
+			return nil, err
+		}
+		// check for dynamic types
+		if isDynamicType(input.Type) {
+			// set the offset
+			ret = append(ret, packNum(reflect.ValueOf(inputOffset))...)
+			// calculate next offset
+			inputOffset += len(packed)
+			// append to variable input
+			variableInput = append(variableInput, packed...)
+		} else {
+			// append the packed value to the input
+			ret = append(ret, packed...)
+		}
+	}
+	// append the variable input at the end of the packed input
+	ret = append(ret, variableInput...)
+
+	return ret, nil
+}
+
+// ToCamelCase converts an under-score string to a camel-case string
+func ToCamelCase(input string) string {
+	parts := strings.Split(input, "_")
+	for i, s := range parts {
+		if len(s) > 0 {
+			parts[i] = strings.ToUpper(s[:1]) + s[1:]
+		}
+	}
+	return strings.Join(parts, "")
+}
diff --git a/accounts/abi/bind/auth.go b/accounts/abi/bind/auth.go
new file mode 100644
index 0000000..c916cc4
--- /dev/null
+++ b/accounts/abi/bind/auth.go
@@ -0,0 +1,96 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import (
+	"crypto/ecdsa"
+	"errors"
+	"io"
+	"io/ioutil"
+
+	"github.com/ava-labs/coreth/accounts"
+	"github.com/ava-labs/coreth/accounts/external"
+	"github.com/ava-labs/coreth/accounts/keystore"
+	"github.com/ava-labs/coreth/core/types"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/crypto"
+)
+
+// NewTransactor is a utility method to easily create a transaction signer from
+// an encrypted json key stream and the associated passphrase.
+func NewTransactor(keyin io.Reader, passphrase string) (*TransactOpts, error) {
+	json, err := ioutil.ReadAll(keyin)
+	if err != nil {
+		return nil, err
+	}
+	key, err := keystore.DecryptKey(json, passphrase)
+	if err != nil {
+		return nil, err
+	}
+	return NewKeyedTransactor(key.PrivateKey), nil
+}
+
+// NewKeyStoreTransactor is a utility method to easily create a transaction signer from
+// an decrypted key from a keystore
+func NewKeyStoreTransactor(keystore *keystore.KeyStore, account accounts.Account) (*TransactOpts, error) {
+	return &TransactOpts{
+		From: account.Address,
+		Signer: func(signer types.Signer, address common.Address, tx *types.Transaction) (*types.Transaction, error) {
+			if address != account.Address {
+				return nil, errors.New("not authorized to sign this account")
+			}
+			signature, err := keystore.SignHash(account, signer.Hash(tx).Bytes())
+			if err != nil {
+				return nil, err
+			}
+			return tx.WithSignature(signer, signature)
+		},
+	}, nil
+}
+
+// NewKeyedTransactor is a utility method to easily create a transaction signer
+// from a single private key.
+func NewKeyedTransactor(key *ecdsa.PrivateKey) *TransactOpts {
+	keyAddr := crypto.PubkeyToAddress(key.PublicKey)
+	return &TransactOpts{
+		From: keyAddr,
+		Signer: func(signer types.Signer, address common.Address, tx *types.Transaction) (*types.Transaction, error) {
+			if address != keyAddr {
+				return nil, errors.New("not authorized to sign this account")
+			}
+			signature, err := crypto.Sign(signer.Hash(tx).Bytes(), key)
+			if err != nil {
+				return nil, err
+			}
+			return tx.WithSignature(signer, signature)
+		},
+	}
+}
+
+// NewClefTransactor is a utility method to easily create a transaction signer
+// with a clef backend.
+func NewClefTransactor(clef *external.ExternalSigner, account accounts.Account) *TransactOpts {
+	return &TransactOpts{
+		From: account.Address,
+		Signer: func(signer types.Signer, address common.Address, transaction *types.Transaction) (*types.Transaction, error) {
+			if address != account.Address {
+				return nil, errors.New("not authorized to sign this account")
+			}
+			return clef.SignTx(account, transaction, nil) // Clef enforces its own chain id
+		},
+	}
+}
diff --git a/accounts/abi/bind/backend.go b/accounts/abi/bind/backend.go
new file mode 100644
index 0000000..556394f
--- /dev/null
+++ b/accounts/abi/bind/backend.go
@@ -0,0 +1,112 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import (
+	"context"
+	"errors"
+	"math/big"
+
+	"github.com/ava-labs/coreth/core/types"
+	"github.com/ava-labs/go-ethereum"
+	"github.com/ava-labs/go-ethereum/common"
+)
+
+var (
+	// ErrNoCode is returned by call and transact operations for which the requested
+	// recipient contract to operate on does not exist in the state db or does not
+	// have any code associated with it (i.e. suicided).
+	ErrNoCode = errors.New("no contract code at given address")
+
+	// This error is raised when attempting to perform a pending state action
+	// on a backend that doesn't implement PendingContractCaller.
+	ErrNoPendingState = errors.New("backend does not support pending state")
+
+	// This error is returned by WaitDeployed if contract creation leaves an
+	// empty contract behind.
+	ErrNoCodeAfterDeploy = errors.New("no contract code after deployment")
+)
+
+// ContractCaller defines the methods needed to allow operating with contract on a read
+// only basis.
+type ContractCaller interface {
+	// CodeAt returns the code of the given account. This is needed to differentiate
+	// between contract internal errors and the local chain being out of sync.
+	CodeAt(ctx context.Context, contract common.Address, blockNumber *big.Int) ([]byte, error)
+	// ContractCall executes an Ethereum contract call with the specified data as the
+	// input.
+	CallContract(ctx context.Context, call ethereum.CallMsg, blockNumber *big.Int) ([]byte, error)
+}
+
+// PendingContractCaller defines methods to perform contract calls on the pending state.
+// Call will try to discover this interface when access to the pending state is requested.
+// If the backend does not support the pending state, Call returns ErrNoPendingState.
+type PendingContractCaller interface {
+	// PendingCodeAt returns the code of the given account in the pending state.
+	PendingCodeAt(ctx context.Context, contract common.Address) ([]byte, error)
+	// PendingCallContract executes an Ethereum contract call against the pending state.
+	PendingCallContract(ctx context.Context, call ethereum.CallMsg) ([]byte, error)
+}
+
+// ContractTransactor defines the methods needed to allow operating with contract
+// on a write only basis. Beside the transacting method, the remainder are helpers
+// used when the user does not provide some needed values, but rather leaves it up
+// to the transactor to decide.
+type ContractTransactor interface {
+	// PendingCodeAt returns the code of the given account in the pending state.
+	PendingCodeAt(ctx context.Context, account common.Address) ([]byte, error)
+	// PendingNonceAt retrieves the current pending nonce associated with an account.
+	PendingNonceAt(ctx context.Context, account common.Address) (uint64, error)
+	// SuggestGasPrice retrieves the currently suggested gas price to allow a timely
+	// execution of a transaction.
+	SuggestGasPrice(ctx context.Context) (*big.Int, error)
+	// EstimateGas tries to estimate the gas needed to execute a specific
+	// transaction based on the current pending state of the backend blockchain.
+	// There is no guarantee that this is the true gas limit requirement as other
+	// transactions may be added or removed by miners, but it should provide a basis
+	// for setting a reasonable default.
+	EstimateGas(ctx context.Context, call ethereum.CallMsg) (gas uint64, err error)
+	// SendTransaction injects the transaction into the pending pool for execution.
+	SendTransaction(ctx context.Context, tx *types.Transaction) error
+}
+
+// ContractFilterer defines the methods needed to access log events using one-off
+// queries or continuous event subscriptions.
+type ContractFilterer interface {
+	// FilterLogs executes a log filter operation, blocking during execution and
+	// returning all the results in one batch.
+	//
+	// TODO(karalabe): Deprecate when the subscription one can return past data too.
+	FilterLogs(ctx context.Context, query ethereum.FilterQuery) ([]types.Log, error)
+
+	// SubscribeFilterLogs creates a background log filtering operation, returning
+	// a subscription immediately, which can be used to stream the found events.
+	SubscribeFilterLogs(ctx context.Context, query ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error)
+}
+
+// DeployBackend wraps the operations needed by WaitMined and WaitDeployed.
+type DeployBackend interface {
+	TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error)
+	CodeAt(ctx context.Context, account common.Address, blockNumber *big.Int) ([]byte, error)
+}
+
+// ContractBackend defines the methods needed to work with contracts on a read-write basis.
+type ContractBackend interface {
+	ContractCaller
+	ContractTransactor
+	ContractFilterer
+}
diff --git a/accounts/abi/bind/backends/simulated.go b/accounts/abi/bind/backends/simulated.go
new file mode 100644
index 0000000..88610a4
--- /dev/null
+++ b/accounts/abi/bind/backends/simulated.go
@@ -0,0 +1,523 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package backends
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"math/big"
+	"sync"
+	"time"
+
+	"github.com/ava-labs/coreth/accounts/abi/bind"
+	"github.com/ava-labs/coreth/consensus/ethash"
+	"github.com/ava-labs/coreth/core"
+	"github.com/ava-labs/coreth/core/bloombits"
+	"github.com/ava-labs/coreth/core/rawdb"
+	"github.com/ava-labs/coreth/core/state"
+	"github.com/ava-labs/coreth/core/types"
+	"github.com/ava-labs/coreth/core/vm"
+	"github.com/ava-labs/coreth/params"
+	"github.com/ava-labs/coreth/rpc"
+	"github.com/ava-labs/go-ethereum"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/common/math"
+	"github.com/ava-labs/go-ethereum/eth/filters"
+	"github.com/ava-labs/go-ethereum/ethdb"
+	"github.com/ava-labs/go-ethereum/event"
+)
+
+// This nil assignment ensures compile time that SimulatedBackend implements bind.ContractBackend.
+var _ bind.ContractBackend = (*SimulatedBackend)(nil)
+
+var (
+	errBlockNumberUnsupported = errors.New("simulatedBackend cannot access blocks other than the latest block")
+	errGasEstimationFailed    = errors.New("gas required exceeds allowance or always failing transaction")
+)
+
+// SimulatedBackend implements bind.ContractBackend, simulating a blockchain in
+// the background. Its main purpose is to allow easily testing contract bindings.
+type SimulatedBackend struct {
+	database   ethdb.Database   // In memory database to store our testing data
+	blockchain *core.BlockChain // Ethereum blockchain to handle the consensus
+
+	mu           sync.Mutex
+	pendingBlock *types.Block   // Currently pending block that will be imported on request
+	pendingState *state.StateDB // Currently pending state that will be the active on on request
+
+	events *filters.EventSystem // Event system for filtering log events live
+
+	config *params.ChainConfig
+}
+
+// NewSimulatedBackendWithDatabase creates a new binding backend based on the given database
+// and uses a simulated blockchain for testing purposes.
+func NewSimulatedBackendWithDatabase(database ethdb.Database, alloc core.GenesisAlloc, gasLimit uint64) *SimulatedBackend {
+	genesis := core.Genesis{Config: params.AllEthashProtocolChanges, GasLimit: gasLimit, Alloc: alloc}
+	genesis.MustCommit(database)
+	blockchain, _ := core.NewBlockChain(database, nil, genesis.Config, ethash.NewFaker(), vm.Config{}, nil)
+
+	backend := &SimulatedBackend{
+		database:   database,
+		blockchain: blockchain,
+		config:     genesis.Config,
+		events:     filters.NewEventSystem(new(event.TypeMux), &filterBackend{database, blockchain}, false),
+	}
+	backend.rollback()
+	return backend
+}
+
+// NewSimulatedBackend creates a new binding backend using a simulated blockchain
+// for testing purposes.
+func NewSimulatedBackend(alloc core.GenesisAlloc, gasLimit uint64) *SimulatedBackend {
+	return NewSimulatedBackendWithDatabase(rawdb.NewMemoryDatabase(), alloc, gasLimit)
+}
+
+// Close terminates the underlying blockchain's update loop.
+func (b *SimulatedBackend) Close() error {
+	b.blockchain.Stop()
+	return nil
+}
+
+// Commit imports all the pending transactions as a single block and starts a
+// fresh new state.
+func (b *SimulatedBackend) Commit() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if _, err := b.blockchain.InsertChain([]*types.Block{b.pendingBlock}); err != nil {
+		panic(err) // This cannot happen unless the simulator is wrong, fail in that case
+	}
+	b.rollback()
+}
+
+// Rollback aborts all pending transactions, reverting to the last committed state.
+func (b *SimulatedBackend) Rollback() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	b.rollback()
+}
+
+func (b *SimulatedBackend) rollback() {
+	blocks, _ := core.GenerateChain(b.config, b.blockchain.CurrentBlock(), ethash.NewFaker(), b.database, 1, func(int, *core.BlockGen) {})
+	statedb, _ := b.blockchain.State()
+
+	b.pendingBlock = blocks[0]
+	b.pendingState, _ = state.New(b.pendingBlock.Root(), statedb.Database())
+}
+
+// CodeAt returns the code associated with a certain account in the blockchain.
+func (b *SimulatedBackend) CodeAt(ctx context.Context, contract common.Address, blockNumber *big.Int) ([]byte, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
+		return nil, errBlockNumberUnsupported
+	}
+	statedb, _ := b.blockchain.State()
+	return statedb.GetCode(contract), nil
+}
+
+// BalanceAt returns the wei balance of a certain account in the blockchain.
+func (b *SimulatedBackend) BalanceAt(ctx context.Context, contract common.Address, blockNumber *big.Int) (*big.Int, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
+		return nil, errBlockNumberUnsupported
+	}
+	statedb, _ := b.blockchain.State()
+	return statedb.GetBalance(contract), nil
+}
+
+// NonceAt returns the nonce of a certain account in the blockchain.
+func (b *SimulatedBackend) NonceAt(ctx context.Context, contract common.Address, blockNumber *big.Int) (uint64, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
+		return 0, errBlockNumberUnsupported
+	}
+	statedb, _ := b.blockchain.State()
+	return statedb.GetNonce(contract), nil
+}
+
+// StorageAt returns the value of key in the storage of an account in the blockchain.
+func (b *SimulatedBackend) StorageAt(ctx context.Context, contract common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
+		return nil, errBlockNumberUnsupported
+	}
+	statedb, _ := b.blockchain.State()
+	val := statedb.GetState(contract, key)
+	return val[:], nil
+}
+
+// TransactionReceipt returns the receipt of a transaction.
+func (b *SimulatedBackend) TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error) {
+	receipt, _, _, _ := rawdb.ReadReceipt(b.database, txHash, b.config)
+	return receipt, nil
+}
+
+// TransactionByHash checks the pool of pending transactions in addition to the
+// blockchain. The isPending return value indicates whether the transaction has been
+// mined yet. Note that the transaction may not be part of the canonical chain even if
+// it's not pending.
+func (b *SimulatedBackend) TransactionByHash(ctx context.Context, txHash common.Hash) (*types.Transaction, bool, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	tx := b.pendingBlock.Transaction(txHash)
+	if tx != nil {
+		return tx, true, nil
+	}
+	tx, _, _, _ = rawdb.ReadTransaction(b.database, txHash)
+	if tx != nil {
+		return tx, false, nil
+	}
+	return nil, false, ethereum.NotFound
+}
+
+// PendingCodeAt returns the code associated with an account in the pending state.
+func (b *SimulatedBackend) PendingCodeAt(ctx context.Context, contract common.Address) ([]byte, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	return b.pendingState.GetCode(contract), nil
+}
+
+// CallContract executes a contract call.
+func (b *SimulatedBackend) CallContract(ctx context.Context, call ethereum.CallMsg, blockNumber *big.Int) ([]byte, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
+		return nil, errBlockNumberUnsupported
+	}
+	state, err := b.blockchain.State()
+	if err != nil {
+		return nil, err
+	}
+	rval, _, _, err := b.callContract(ctx, call, b.blockchain.CurrentBlock(), state)
+	return rval, err
+}
+
+// PendingCallContract executes a contract call on the pending state.
+func (b *SimulatedBackend) PendingCallContract(ctx context.Context, call ethereum.CallMsg) ([]byte, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	defer b.pendingState.RevertToSnapshot(b.pendingState.Snapshot())
+
+	rval, _, _, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState)
+	return rval, err
+}
+
+// PendingNonceAt implements PendingStateReader.PendingNonceAt, retrieving
+// the nonce currently pending for the account.
+func (b *SimulatedBackend) PendingNonceAt(ctx context.Context, account common.Address) (uint64, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	return b.pendingState.GetOrNewStateObject(account).Nonce(), nil
+}
+
+// SuggestGasPrice implements ContractTransactor.SuggestGasPrice. Since the simulated
+// chain doesn't have miners, we just return a gas price of 1 for any call.
+func (b *SimulatedBackend) SuggestGasPrice(ctx context.Context) (*big.Int, error) {
+	return big.NewInt(1), nil
+}
+
+// EstimateGas executes the requested code against the currently pending block/state and
+// returns the used amount of gas.
+func (b *SimulatedBackend) EstimateGas(ctx context.Context, call ethereum.CallMsg) (uint64, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	// Determine the lowest and highest possible gas limits to binary search in between
+	var (
+		lo  uint64 = params.TxGas - 1
+		hi  uint64
+		cap uint64
+	)
+	if call.Gas >= params.TxGas {
+		hi = call.Gas
+	} else {
+		hi = b.pendingBlock.GasLimit()
+	}
+	cap = hi
+
+	// Create a helper to check if a gas allowance results in an executable transaction
+	executable := func(gas uint64) bool {
+		call.Gas = gas
+
+		snapshot := b.pendingState.Snapshot()
+		_, _, failed, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState)
+		b.pendingState.RevertToSnapshot(snapshot)
+
+		if err != nil || failed {
+			return false
+		}
+		return true
+	}
+	// Execute the binary search and hone in on an executable gas limit
+	for lo+1 < hi {
+		mid := (hi + lo) / 2
+		if !executable(mid) {
+			lo = mid
+		} else {
+			hi = mid
+		}
+	}
+	// Reject the transaction as invalid if it still fails at the highest allowance
+	if hi == cap {
+		if !executable(hi) {
+			return 0, errGasEstimationFailed
+		}
+	}
+	return hi, nil
+}
+
+// callContract implements common code between normal and pending contract calls.
+// state is modified during execution, make sure to copy it if necessary.
+func (b *SimulatedBackend) callContract(ctx context.Context, call ethereum.CallMsg, block *types.Block, statedb *state.StateDB) ([]byte, uint64, bool, error) {
+	// Ensure message is initialized properly.
+	if call.GasPrice == nil {
+		call.GasPrice = big.NewInt(1)
+	}
+	if call.Gas == 0 {
+		call.Gas = 50000000
+	}
+	if call.Value == nil {
+		call.Value = new(big.Int)
+	}
+	// Set infinite balance to the fake caller account.
+	from := statedb.GetOrNewStateObject(call.From)
+	from.SetBalance(math.MaxBig256)
+	// Execute the call.
+	msg := callmsg{call}
+
+	evmContext := core.NewEVMContext(msg, block.Header(), b.blockchain, nil)
+	// Create a new environment which holds all relevant information
+	// about the transaction and calling mechanisms.
+	vmenv := vm.NewEVM(evmContext, statedb, b.config, vm.Config{})
+	gaspool := new(core.GasPool).AddGas(math.MaxUint64)
+
+	return core.NewStateTransition(vmenv, msg, gaspool).TransitionDb()
+}
+
+// SendTransaction updates the pending block to include the given transaction.
+// It panics if the transaction is invalid.
+func (b *SimulatedBackend) SendTransaction(ctx context.Context, tx *types.Transaction) error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	sender, err := types.Sender(types.NewEIP155Signer(b.config.ChainID), tx)
+	if err != nil {
+		panic(fmt.Errorf("invalid transaction: %v", err))
+	}
+	nonce := b.pendingState.GetNonce(sender)
+	if tx.Nonce() != nonce {
+		panic(fmt.Errorf("invalid transaction nonce: got %d, want %d", tx.Nonce(), nonce))
+	}
+
+	blocks, _ := core.GenerateChain(b.config, b.blockchain.CurrentBlock(), ethash.NewFaker(), b.database, 1, func(number int, block *core.BlockGen) {
+		for _, tx := range b.pendingBlock.Transactions() {
+			block.AddTxWithChain(b.blockchain, tx)
+		}
+		block.AddTxWithChain(b.blockchain, tx)
+	})
+	statedb, _ := b.blockchain.State()
+
+	b.pendingBlock = blocks[0]
+	b.pendingState, _ = state.New(b.pendingBlock.Root(), statedb.Database())
+	return nil
+}
+
+// FilterLogs executes a log filter operation, blocking during execution and
+// returning all the results in one batch.
+//
+// TODO(karalabe): Deprecate when the subscription one can return past data too.
+func (b *SimulatedBackend) FilterLogs(ctx context.Context, query ethereum.FilterQuery) ([]types.Log, error) {
+	var filter *filters.Filter
+	if query.BlockHash != nil {
+		// Block filter requested, construct a single-shot filter
+		filter = filters.NewBlockFilter(&filterBackend{b.database, b.blockchain}, *query.BlockHash, query.Addresses, query.Topics)
+	} else {
+		// Initialize unset filter boundaried to run from genesis to chain head
+		from := int64(0)
+		if query.FromBlock != nil {
+			from = query.FromBlock.Int64()
+		}
+		to := int64(-1)
+		if query.ToBlock != nil {
+			to = query.ToBlock.Int64()
+		}
+		// Construct the range filter
+		filter = filters.NewRangeFilter(&filterBackend{b.database, b.blockchain}, from, to, query.Addresses, query.Topics)
+	}
+	// Run the filter and return all the logs
+	logs, err := filter.Logs(ctx)
+	if err != nil {
+		return nil, err
+	}
+	res := make([]types.Log, len(logs))
+	for i, log := range logs {
+		res[i] = *log
+	}
+	return res, nil
+}
+
+// SubscribeFilterLogs creates a background log filtering operation, returning a
+// subscription immediately, which can be used to stream the found events.
+func (b *SimulatedBackend) SubscribeFilterLogs(ctx context.Context, query ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error) {
+	// Subscribe to contract events
+	sink := make(chan []*types.Log)
+
+	sub, err := b.events.SubscribeLogs(query, sink)
+	if err != nil {
+		return nil, err
+	}
+	// Since we're getting logs in batches, we need to flatten them into a plain stream
+	return event.NewSubscription(func(quit <-chan struct{}) error {
+		defer sub.Unsubscribe()
+		for {
+			select {
+			case logs := <-sink:
+				for _, log := range logs {
+					select {
+					case ch <- *log:
+					case err := <-sub.Err():
+						return err
+					case <-quit:
+						return nil
+					}
+				}
+			case err := <-sub.Err():
+				return err
+			case <-quit:
+				return nil
+			}
+		}
+	}), nil
+}
+
+// AdjustTime adds a time shift to the simulated clock.
+func (b *SimulatedBackend) AdjustTime(adjustment time.Duration) error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	blocks, _ := core.GenerateChain(b.config, b.blockchain.CurrentBlock(), ethash.NewFaker(), b.database, 1, func(number int, block *core.BlockGen) {
+		for _, tx := range b.pendingBlock.Transactions() {
+			block.AddTx(tx)
+		}
+		block.OffsetTime(int64(adjustment.Seconds()))
+	})
+	statedb, _ := b.blockchain.State()
+
+	b.pendingBlock = blocks[0]
+	b.pendingState, _ = state.New(b.pendingBlock.Root(), statedb.Database())
+
+	return nil
+}
+
+// Blockchain returns the underlying blockchain.
+func (b *SimulatedBackend) Blockchain() *core.BlockChain {
+	return b.blockchain
+}
+
+// callmsg implements core.Message to allow passing it as a transaction simulator.
+type callmsg struct {
+	ethereum.CallMsg
+}
+
+func (m callmsg) From() common.Address { return m.CallMsg.From }
+func (m callmsg) Nonce() uint64        { return 0 }
+func (m callmsg) CheckNonce() bool     { return false }
+func (m callmsg) To() *common.Address  { return m.CallMsg.To }
+func (m callmsg) GasPrice() *big.Int   { return m.CallMsg.GasPrice }
+func (m callmsg) Gas() uint64          { return m.CallMsg.Gas }
+func (m callmsg) Value() *big.Int      { return m.CallMsg.Value }
+func (m callmsg) Data() []byte         { return m.CallMsg.Data }
+
+// filterBackend implements filters.Backend to support filtering for logs without
+// taking bloom-bits acceleration structures into account.
+type filterBackend struct {
+	db ethdb.Database
+	bc *core.BlockChain
+}
+
+func (fb *filterBackend) ChainDb() ethdb.Database  { return fb.db }
+func (fb *filterBackend) EventMux() *event.TypeMux { panic("not supported") }
+
+func (fb *filterBackend) HeaderByNumber(ctx context.Context, block rpc.BlockNumber) (*types.Header, error) {
+	if block == rpc.LatestBlockNumber {
+		return fb.bc.CurrentHeader(), nil
+	}
+	return fb.bc.GetHeaderByNumber(uint64(block.Int64())), nil
+}
+
+func (fb *filterBackend) HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error) {
+	return fb.bc.GetHeaderByHash(hash), nil
+}
+
+func (fb *filterBackend) GetReceipts(ctx context.Context, hash common.Hash) (types.Receipts, error) {
+	number := rawdb.ReadHeaderNumber(fb.db, hash)
+	if number == nil {
+		return nil, nil
+	}
+	return rawdb.ReadReceipts(fb.db, hash, *number, fb.bc.Config()), nil
+}
+
+func (fb *filterBackend) GetLogs(ctx context.Context, hash common.Hash) ([][]*types.Log, error) {
+	number := rawdb.ReadHeaderNumber(fb.db, hash)
+	if number == nil {
+		return nil, nil
+	}
+	receipts := rawdb.ReadReceipts(fb.db, hash, *number, fb.bc.Config())
+	if receipts == nil {
+		return nil, nil
+	}
+	logs := make([][]*types.Log, len(receipts))
+	for i, receipt := range receipts {
+		logs[i] = receipt.Logs
+	}
+	return logs, nil
+}
+
+func (fb *filterBackend) SubscribeNewTxsEvent(ch chan<- core.NewTxsEvent) event.Subscription {
+	return event.NewSubscription(func(quit <-chan struct{}) error {
+		<-quit
+		return nil
+	})
+}
+func (fb *filterBackend) SubscribeChainEvent(ch chan<- core.ChainEvent) event.Subscription {
+	return fb.bc.SubscribeChainEvent(ch)
+}
+func (fb *filterBackend) SubscribeRemovedLogsEvent(ch chan<- core.RemovedLogsEvent) event.Subscription {
+	return fb.bc.SubscribeRemovedLogsEvent(ch)
+}
+func (fb *filterBackend) SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscription {
+	return fb.bc.SubscribeLogsEvent(ch)
+}
+
+func (fb *filterBackend) BloomStatus() (uint64, uint64) { return 4096, 0 }
+func (fb *filterBackend) ServiceFilter(ctx context.Context, ms *bloombits.MatcherSession) {
+	panic("not supported")
+}
diff --git a/accounts/abi/bind/base.go b/accounts/abi/bind/base.go
new file mode 100644
index 0000000..3d64f85
--- /dev/null
+++ b/accounts/abi/bind/base.go
@@ -0,0 +1,366 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"math/big"
+
+	"github.com/ava-labs/coreth/accounts/abi"
+	"github.com/ava-labs/coreth/core/types"
+	"github.com/ava-labs/go-ethereum"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/crypto"
+	"github.com/ava-labs/go-ethereum/event"
+)
+
+// SignerFn is a signer function callback when a contract requires a method to
+// sign the transaction before submission.
+type SignerFn func(types.Signer, common.Address, *types.Transaction) (*types.Transaction, error)
+
+// CallOpts is the collection of options to fine tune a contract call request.
+type CallOpts struct {
+	Pending     bool            // Whether to operate on the pending state or the last known one
+	From        common.Address  // Optional the sender address, otherwise the first account is used
+	BlockNumber *big.Int        // Optional the block number on which the call should be performed
+	Context     context.Context // Network context to support cancellation and timeouts (nil = no timeout)
+}
+
+// TransactOpts is the collection of authorization data required to create a
+// valid Ethereum transaction.
+type TransactOpts struct {
+	From   common.Address // Ethereum account to send the transaction from
+	Nonce  *big.Int       // Nonce to use for the transaction execution (nil = use pending state)
+	Signer SignerFn       // Method to use for signing the transaction (mandatory)
+
+	Value    *big.Int // Funds to transfer along along the transaction (nil = 0 = no funds)
+	GasPrice *big.Int // Gas price to use for the transaction execution (nil = gas price oracle)
+	GasLimit uint64   // Gas limit to set for the transaction execution (0 = estimate)
+
+	Context context.Context // Network context to support cancellation and timeouts (nil = no timeout)
+}
+
+// FilterOpts is the collection of options to fine tune filtering for events
+// within a bound contract.
+type FilterOpts struct {
+	Start uint64  // Start of the queried range
+	End   *uint64 // End of the range (nil = latest)
+
+	Context context.Context // Network context to support cancellation and timeouts (nil = no timeout)
+}
+
+// WatchOpts is the collection of options to fine tune subscribing for events
+// within a bound contract.
+type WatchOpts struct {
+	Start   *uint64         // Start of the queried range (nil = latest)
+	Context context.Context // Network context to support cancellation and timeouts (nil = no timeout)
+}
+
+// BoundContract is the base wrapper object that reflects a contract on the
+// Ethereum network. It contains a collection of methods that are used by the
+// higher level contract bindings to operate.
+type BoundContract struct {
+	address    common.Address     // Deployment address of the contract on the Ethereum blockchain
+	abi        abi.ABI            // Reflect based ABI to access the correct Ethereum methods
+	caller     ContractCaller     // Read interface to interact with the blockchain
+	transactor ContractTransactor // Write interface to interact with the blockchain
+	filterer   ContractFilterer   // Event filtering to interact with the blockchain
+}
+
+// NewBoundContract creates a low level contract interface through which calls
+// and transactions may be made through.
+func NewBoundContract(address common.Address, abi abi.ABI, caller ContractCaller, transactor ContractTransactor, filterer ContractFilterer) *BoundContract {
+	return &BoundContract{
+		address:    address,
+		abi:        abi,
+		caller:     caller,
+		transactor: transactor,
+		filterer:   filterer,
+	}
+}
+
+// DeployContract deploys a contract onto the Ethereum blockchain and binds the
+// deployment address with a Go wrapper.
+func DeployContract(opts *TransactOpts, abi abi.ABI, bytecode []byte, backend ContractBackend, params ...interface{}) (common.Address, *types.Transaction, *BoundContract, error) {
+	// Otherwise try to deploy the contract
+	c := NewBoundContract(common.Address{}, abi, backend, backend, backend)
+
+	input, err := c.abi.Pack("", params...)
+	if err != nil {
+		return common.Address{}, nil, nil, err
+	}
+	tx, err := c.transact(opts, nil, append(bytecode, input...))
+	if err != nil {
+		return common.Address{}, nil, nil, err
+	}
+	c.address = crypto.CreateAddress(opts.From, tx.Nonce())
+	return c.address, tx, c, nil
+}
+
+// Call invokes the (constant) contract method with params as input values and
+// sets the output to result. The result type might be a single field for simple
+// returns, a slice of interfaces for anonymous returns and a struct for named
+// returns.
+func (c *BoundContract) Call(opts *CallOpts, result interface{}, method string, params ...interface{}) error {
+	// Don't crash on a lazy user
+	if opts == nil {
+		opts = new(CallOpts)
+	}
+	// Pack the input, call and unpack the results
+	input, err := c.abi.Pack(method, params...)
+	if err != nil {
+		return err
+	}
+	var (
+		msg    = ethereum.CallMsg{From: opts.From, To: &c.address, Data: input}
+		ctx    = ensureContext(opts.Context)
+		code   []byte
+		output []byte
+	)
+	if opts.Pending {
+		pb, ok := c.caller.(PendingContractCaller)
+		if !ok {
+			return ErrNoPendingState
+		}
+		output, err = pb.PendingCallContract(ctx, msg)
+		if err == nil && len(output) == 0 {
+			// Make sure we have a contract to operate on, and bail out otherwise.
+			if code, err = pb.PendingCodeAt(ctx, c.address); err != nil {
+				return err
+			} else if len(code) == 0 {
+				return ErrNoCode
+			}
+		}
+	} else {
+		output, err = c.caller.CallContract(ctx, msg, opts.BlockNumber)
+		if err == nil && len(output) == 0 {
+			// Make sure we have a contract to operate on, and bail out otherwise.
+			if code, err = c.caller.CodeAt(ctx, c.address, opts.BlockNumber); err != nil {
+				return err
+			} else if len(code) == 0 {
+				return ErrNoCode
+			}
+		}
+	}
+	if err != nil {
+		return err
+	}
+	return c.abi.Unpack(result, method, output)
+}
+
+// Transact invokes the (paid) contract method with params as input values.
+func (c *BoundContract) Transact(opts *TransactOpts, method string, params ...interface{}) (*types.Transaction, error) {
+	// Otherwise pack up the parameters and invoke the contract
+	input, err := c.abi.Pack(method, params...)
+	if err != nil {
+		return nil, err
+	}
+	return c.transact(opts, &c.address, input)
+}
+
+// Transfer initiates a plain transaction to move funds to the contract, calling
+// its default method if one is available.
+func (c *BoundContract) Transfer(opts *TransactOpts) (*types.Transaction, error) {
+	return c.transact(opts, &c.address, nil)
+}
+
+// transact executes an actual transaction invocation, first deriving any missing
+// authorization fields, and then scheduling the transaction for execution.
+func (c *BoundContract) transact(opts *TransactOpts, contract *common.Address, input []byte) (*types.Transaction, error) {
+	var err error
+
+	// Ensure a valid value field and resolve the account nonce
+	value := opts.Value
+	if value == nil {
+		value = new(big.Int)
+	}
+	var nonce uint64
+	if opts.Nonce == nil {
+		nonce, err = c.transactor.PendingNonceAt(ensureContext(opts.Context), opts.From)
+		if err != nil {
+			return nil, fmt.Errorf("failed to retrieve account nonce: %v", err)
+		}
+	} else {
+		nonce = opts.Nonce.Uint64()
+	}
+	// Figure out the gas allowance and gas price values
+	gasPrice := opts.GasPrice
+	if gasPrice == nil {
+		gasPrice, err = c.transactor.SuggestGasPrice(ensureContext(opts.Context))
+		if err != nil {
+			return nil, fmt.Errorf("failed to suggest gas price: %v", err)
+		}
+	}
+	gasLimit := opts.GasLimit
+	if gasLimit == 0 {
+		// Gas estimation cannot succeed without code for method invocations
+		if contract != nil {
+			if code, err := c.transactor.PendingCodeAt(ensureContext(opts.Context), c.address); err != nil {
+				return nil, err
+			} else if len(code) == 0 {
+				return nil, ErrNoCode
+			}
+		}
+		// If the contract surely has code (or code is not needed), estimate the transaction
+		msg := ethereum.CallMsg{From: opts.From, To: contract, Value: value, Data: input}
+		gasLimit, err = c.transactor.EstimateGas(ensureContext(opts.Context), msg)
+		if err != nil {
+			return nil, fmt.Errorf("failed to estimate gas needed: %v", err)
+		}
+	}
+	// Create the transaction, sign it and schedule it for execution
+	var rawTx *types.Transaction
+	if contract == nil {
+		rawTx = types.NewContractCreation(nonce, value, gasLimit, gasPrice, input)
+	} else {
+		rawTx = types.NewTransaction(nonce, c.address, value, gasLimit, gasPrice, input)
+	}
+	if opts.Signer == nil {
+		return nil, errors.New("no signer to authorize the transaction with")
+	}
+	signedTx, err := opts.Signer(types.HomesteadSigner{}, opts.From, rawTx)
+	if err != nil {
+		return nil, err
+	}
+	if err := c.transactor.SendTransaction(ensureContext(opts.Context), signedTx); err != nil {
+		return nil, err
+	}
+	return signedTx, nil
+}
+
+// FilterLogs filters contract logs for past blocks, returning the necessary
+// channels to construct a strongly typed bound iterator on top of them.
+func (c *BoundContract) FilterLogs(opts *FilterOpts, name string, query ...[]interface{}) (chan types.Log, event.Subscription, error) {
+	// Don't crash on a lazy user
+	if opts == nil {
+		opts = new(FilterOpts)
+	}
+	// Append the event selector to the query parameters and construct the topic set
+	query = append([][]interface{}{{c.abi.Events[name].ID()}}, query...)
+
+	topics, err := makeTopics(query...)
+	if err != nil {
+		return nil, nil, err
+	}
+	// Start the background filtering
+	logs := make(chan types.Log, 128)
+
+	config := ethereum.FilterQuery{
+		Addresses: []common.Address{c.address},
+		Topics:    topics,
+		FromBlock: new(big.Int).SetUint64(opts.Start),
+	}
+	if opts.End != nil {
+		config.ToBlock = new(big.Int).SetUint64(*opts.End)
+	}
+	/* TODO(karalabe): Replace the rest of the method below with this when supported
+	sub, err := c.filterer.SubscribeFilterLogs(ensureContext(opts.Context), config, logs)
+	*/
+	buff, err := c.filterer.FilterLogs(ensureContext(opts.Context), config)
+	if err != nil {
+		return nil, nil, err
+	}
+	sub, err := event.NewSubscription(func(quit <-chan struct{}) error {
+		for _, log := range buff {
+			select {
+			case logs <- log:
+			case <-quit:
+				return nil
+			}
+		}
+		return nil
+	}), nil
+
+	if err != nil {
+		return nil, nil, err
+	}
+	return logs, sub, nil
+}
+
+// WatchLogs filters subscribes to contract logs for future blocks, returning a
+// subscription object that can be used to tear down the watcher.
+func (c *BoundContract) WatchLogs(opts *WatchOpts, name string, query ...[]interface{}) (chan types.Log, event.Subscription, error) {
+	// Don't crash on a lazy user
+	if opts == nil {
+		opts = new(WatchOpts)
+	}
+	// Append the event selector to the query parameters and construct the topic set
+	query = append([][]interface{}{{c.abi.Events[name].ID()}}, query...)
+
+	topics, err := makeTopics(query...)
+	if err != nil {
+		return nil, nil, err
+	}
+	// Start the background filtering
+	logs := make(chan types.Log, 128)
+
+	config := ethereum.FilterQuery{
+		Addresses: []common.Address{c.address},
+		Topics:    topics,
+	}
+	if opts.Start != nil {
+		config.FromBlock = new(big.Int).SetUint64(*opts.Start)
+	}
+	sub, err := c.filterer.SubscribeFilterLogs(ensureContext(opts.Context), config, logs)
+	if err != nil {
+		return nil, nil, err
+	}
+	return logs, sub, nil
+}
+
+// UnpackLog unpacks a retrieved log into the provided output structure.
+func (c *BoundContract) UnpackLog(out interface{}, event string, log types.Log) error {
+	if len(log.Data) > 0 {
+		if err := c.abi.Unpack(out, event, log.Data); err != nil {
+			return err
+		}
+	}
+	var indexed abi.Arguments
+	for _, arg := range c.abi.Events[event].Inputs {
+		if arg.Indexed {
+			indexed = append(indexed, arg)
+		}
+	}
+	return parseTopics(out, indexed, log.Topics[1:])
+}
+
+// UnpackLogIntoMap unpacks a retrieved log into the provided map.
+func (c *BoundContract) UnpackLogIntoMap(out map[string]interface{}, event string, log types.Log) error {
+	if len(log.Data) > 0 {
+		if err := c.abi.UnpackIntoMap(out, event, log.Data); err != nil {
+			return err
+		}
+	}
+	var indexed abi.Arguments
+	for _, arg := range c.abi.Events[event].Inputs {
+		if arg.Indexed {
+			indexed = append(indexed, arg)
+		}
+	}
+	return parseTopicsIntoMap(out, indexed, log.Topics[1:])
+}
+
+// ensureContext is a helper method to ensure a context is not nil, even if the
+// user specified it as such.
+func ensureContext(ctx context.Context) context.Context {
+	if ctx == nil {
+		return context.TODO()
+	}
+	return ctx
+}
diff --git a/accounts/abi/bind/bind.go b/accounts/abi/bind/bind.go
new file mode 100644
index 0000000..e869eef
--- /dev/null
+++ b/accounts/abi/bind/bind.go
@@ -0,0 +1,558 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package bind generates Ethereum contract Go bindings.
+//
+// Detailed usage document and tutorial available on the go-ethereum Wiki page:
+// https://github.com/ethereum/go-ethereum/wiki/Native-DApps:-Go-bindings-to-Ethereum-contracts
+package bind
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"go/format"
+	"regexp"
+	"strings"
+	"text/template"
+	"unicode"
+
+	"github.com/ava-labs/coreth/accounts/abi"
+	"github.com/ava-labs/go-ethereum/log"
+)
+
+// Lang is a target programming language selector to generate bindings for.
+type Lang int
+
+const (
+	LangGo Lang = iota
+	LangJava
+	LangObjC
+)
+
+// Bind generates a Go wrapper around a contract ABI. This wrapper isn't meant
+// to be used as is in client code, but rather as an intermediate struct which
+// enforces compile time type safety and naming convention opposed to having to
+// manually maintain hard coded strings that break on runtime.
+func Bind(types []string, abis []string, bytecodes []string, fsigs []map[string]string, pkg string, lang Lang, libs map[string]string) (string, error) {
+	// Process each individual contract requested binding
+	contracts := make(map[string]*tmplContract)
+
+	// Map used to flag each encountered library as such
+	isLib := make(map[string]struct{})
+
+	for i := 0; i < len(types); i++ {
+		// Parse the actual ABI to generate the binding for
+		evmABI, err := abi.JSON(strings.NewReader(abis[i]))
+		if err != nil {
+			return "", err
+		}
+		// Strip any whitespace from the JSON ABI
+		strippedABI := strings.Map(func(r rune) rune {
+			if unicode.IsSpace(r) {
+				return -1
+			}
+			return r
+		}, abis[i])
+
+		// Extract the call and transact methods; events, struct definitions; and sort them alphabetically
+		var (
+			calls     = make(map[string]*tmplMethod)
+			transacts = make(map[string]*tmplMethod)
+			events    = make(map[string]*tmplEvent)
+			structs   = make(map[string]*tmplStruct)
+		)
+		for _, original := range evmABI.Methods {
+			// Normalize the method for capital cases and non-anonymous inputs/outputs
+			normalized := original
+			normalized.Name = methodNormalizer[lang](original.Name)
+
+			normalized.Inputs = make([]abi.Argument, len(original.Inputs))
+			copy(normalized.Inputs, original.Inputs)
+			for j, input := range normalized.Inputs {
+				if input.Name == "" {
+					normalized.Inputs[j].Name = fmt.Sprintf("arg%d", j)
+				}
+				if _, exist := structs[input.Type.String()]; input.Type.T == abi.TupleTy && !exist {
+					bindStructType[lang](input.Type, structs)
+				}
+			}
+			normalized.Outputs = make([]abi.Argument, len(original.Outputs))
+			copy(normalized.Outputs, original.Outputs)
+			for j, output := range normalized.Outputs {
+				if output.Name != "" {
+					normalized.Outputs[j].Name = capitalise(output.Name)
+				}
+				if _, exist := structs[output.Type.String()]; output.Type.T == abi.TupleTy && !exist {
+					bindStructType[lang](output.Type, structs)
+				}
+			}
+			// Append the methods to the call or transact lists
+			if original.Const {
+				calls[original.Name] = &tmplMethod{Original: original, Normalized: normalized, Structured: structured(original.Outputs)}
+			} else {
+				transacts[original.Name] = &tmplMethod{Original: original, Normalized: normalized, Structured: structured(original.Outputs)}
+			}
+		}
+		for _, original := range evmABI.Events {
+			// Skip anonymous events as they don't support explicit filtering
+			if original.Anonymous {
+				continue
+			}
+			// Normalize the event for capital cases and non-anonymous outputs
+			normalized := original
+			normalized.Name = methodNormalizer[lang](original.Name)
+
+			normalized.Inputs = make([]abi.Argument, len(original.Inputs))
+			copy(normalized.Inputs, original.Inputs)
+			for j, input := range normalized.Inputs {
+				// Indexed fields are input, non-indexed ones are outputs
+				if input.Indexed {
+					if input.Name == "" {
+						normalized.Inputs[j].Name = fmt.Sprintf("arg%d", j)
+					}
+					if _, exist := structs[input.Type.String()]; input.Type.T == abi.TupleTy && !exist {
+						bindStructType[lang](input.Type, structs)
+					}
+				}
+			}
+			// Append the event to the accumulator list
+			events[original.Name] = &tmplEvent{Original: original, Normalized: normalized}
+		}
+
+		// There is no easy way to pass arbitrary java objects to the Go side.
+		if len(structs) > 0 && lang == LangJava {
+			return "", errors.New("java binding for tuple arguments is not supported yet")
+		}
+
+		contracts[types[i]] = &tmplContract{
+			Type:        capitalise(types[i]),
+			InputABI:    strings.Replace(strippedABI, "\"", "\\\"", -1),
+			InputBin:    strings.TrimPrefix(strings.TrimSpace(bytecodes[i]), "0x"),
+			Constructor: evmABI.Constructor,
+			Calls:       calls,
+			Transacts:   transacts,
+			Events:      events,
+			Libraries:   make(map[string]string),
+			Structs:     structs,
+		}
+		// Function 4-byte signatures are stored in the same sequence
+		// as types, if available.
+		if len(fsigs) > i {
+			contracts[types[i]].FuncSigs = fsigs[i]
+		}
+		// Parse library references.
+		for pattern, name := range libs {
+			matched, err := regexp.Match("__\\$"+pattern+"\\$__", []byte(contracts[types[i]].InputBin))
+			if err != nil {
+				log.Error("Could not search for pattern", "pattern", pattern, "contract", contracts[types[i]], "err", err)
+			}
+			if matched {
+				contracts[types[i]].Libraries[pattern] = name
+				// keep track that this type is a library
+				if _, ok := isLib[name]; !ok {
+					isLib[name] = struct{}{}
+				}
+			}
+		}
+	}
+	// Check if that type has already been identified as a library
+	for i := 0; i < len(types); i++ {
+		_, ok := isLib[types[i]]
+		contracts[types[i]].Library = ok
+	}
+	// Generate the contract template data content and render it
+	data := &tmplData{
+		Package:   pkg,
+		Contracts: contracts,
+		Libraries: libs,
+	}
+	buffer := new(bytes.Buffer)
+
+	funcs := map[string]interface{}{
+		"bindtype":      bindType[lang],
+		"bindtopictype": bindTopicType[lang],
+		"namedtype":     namedType[lang],
+		"formatmethod":  formatMethod,
+		"formatevent":   formatEvent,
+		"capitalise":    capitalise,
+		"decapitalise":  decapitalise,
+	}
+	tmpl := template.Must(template.New("").Funcs(funcs).Parse(tmplSource[lang]))
+	if err := tmpl.Execute(buffer, data); err != nil {
+		return "", err
+	}
+	// For Go bindings pass the code through gofmt to clean it up
+	if lang == LangGo {
+		code, err := format.Source(buffer.Bytes())
+		if err != nil {
+			return "", fmt.Errorf("%v\n%s", err, buffer)
+		}
+		return string(code), nil
+	}
+	// For all others just return as is for now
+	return buffer.String(), nil
+}
+
+// bindType is a set of type binders that convert Solidity types to some supported
+// programming language types.
+var bindType = map[Lang]func(kind abi.Type, structs map[string]*tmplStruct) string{
+	LangGo:   bindTypeGo,
+	LangJava: bindTypeJava,
+}
+
+// bindBasicTypeGo converts basic solidity types(except array, slice and tuple) to Go one.
+func bindBasicTypeGo(kind abi.Type) string {
+	switch kind.T {
+	case abi.AddressTy:
+		return "common.Address"
+	case abi.IntTy, abi.UintTy:
+		parts := regexp.MustCompile(`(u)?int([0-9]*)`).FindStringSubmatch(kind.String())
+		switch parts[2] {
+		case "8", "16", "32", "64":
+			return fmt.Sprintf("%sint%s", parts[1], parts[2])
+		}
+		return "*big.Int"
+	case abi.FixedBytesTy:
+		return fmt.Sprintf("[%d]byte", kind.Size)
+	case abi.BytesTy:
+		return "[]byte"
+	case abi.FunctionTy:
+		return "[24]byte"
+	default:
+		// string, bool types
+		return kind.String()
+	}
+}
+
+// bindTypeGo converts solidity types to Go ones. Since there is no clear mapping
+// from all Solidity types to Go ones (e.g. uint17), those that cannot be exactly
+// mapped will use an upscaled type (e.g. BigDecimal).
+func bindTypeGo(kind abi.Type, structs map[string]*tmplStruct) string {
+	switch kind.T {
+	case abi.TupleTy:
+		return structs[kind.String()].Name
+	case abi.ArrayTy:
+		return fmt.Sprintf("[%d]", kind.Size) + bindTypeGo(*kind.Elem, structs)
+	case abi.SliceTy:
+		return "[]" + bindTypeGo(*kind.Elem, structs)
+	default:
+		return bindBasicTypeGo(kind)
+	}
+}
+
+// bindBasicTypeJava converts basic solidity types(except array, slice and tuple) to Java one.
+func bindBasicTypeJava(kind abi.Type) string {
+	switch kind.T {
+	case abi.AddressTy:
+		return "Address"
+	case abi.IntTy, abi.UintTy:
+		// Note that uint and int (without digits) are also matched,
+		// these are size 256, and will translate to BigInt (the default).
+		parts := regexp.MustCompile(`(u)?int([0-9]*)`).FindStringSubmatch(kind.String())
+		if len(parts) != 3 {
+			return kind.String()
+		}
+		// All unsigned integers should be translated to BigInt since gomobile doesn't
+		// support them.
+		if parts[1] == "u" {
+			return "BigInt"
+		}
+
+		namedSize := map[string]string{
+			"8":  "byte",
+			"16": "short",
+			"32": "int",
+			"64": "long",
+		}[parts[2]]
+
+		// default to BigInt
+		if namedSize == "" {
+			namedSize = "BigInt"
+		}
+		return namedSize
+	case abi.FixedBytesTy, abi.BytesTy:
+		return "byte[]"
+	case abi.BoolTy:
+		return "boolean"
+	case abi.StringTy:
+		return "String"
+	case abi.FunctionTy:
+		return "byte[24]"
+	default:
+		return kind.String()
+	}
+}
+
+// pluralizeJavaType explicitly converts multidimensional types to predefined
+// type in go side.
+func pluralizeJavaType(typ string) string {
+	switch typ {
+	case "boolean":
+		return "Bools"
+	case "String":
+		return "Strings"
+	case "Address":
+		return "Addresses"
+	case "byte[]":
+		return "Binaries"
+	case "BigInt":
+		return "BigInts"
+	}
+	return typ + "[]"
+}
+
+// bindTypeJava converts a Solidity type to a Java one. Since there is no clear mapping
+// from all Solidity types to Java ones (e.g. uint17), those that cannot be exactly
+// mapped will use an upscaled type (e.g. BigDecimal).
+func bindTypeJava(kind abi.Type, structs map[string]*tmplStruct) string {
+	switch kind.T {
+	case abi.TupleTy:
+		return structs[kind.String()].Name
+	case abi.ArrayTy, abi.SliceTy:
+		return pluralizeJavaType(bindTypeJava(*kind.Elem, structs))
+	default:
+		return bindBasicTypeJava(kind)
+	}
+}
+
+// bindTopicType is a set of type binders that convert Solidity types to some
+// supported programming language topic types.
+var bindTopicType = map[Lang]func(kind abi.Type, structs map[string]*tmplStruct) string{
+	LangGo:   bindTopicTypeGo,
+	LangJava: bindTopicTypeJava,
+}
+
+// bindTopicTypeGo converts a Solidity topic type to a Go one. It is almost the same
+// funcionality as for simple types, but dynamic types get converted to hashes.
+func bindTopicTypeGo(kind abi.Type, structs map[string]*tmplStruct) string {
+	bound := bindTypeGo(kind, structs)
+	if bound == "string" || bound == "[]byte" {
+		bound = "common.Hash"
+	}
+	return bound
+}
+
+// bindTopicTypeJava converts a Solidity topic type to a Java one. It is almost the same
+// funcionality as for simple types, but dynamic types get converted to hashes.
+func bindTopicTypeJava(kind abi.Type, structs map[string]*tmplStruct) string {
+	bound := bindTypeJava(kind, structs)
+	if bound == "String" || bound == "byte[]" {
+		bound = "Hash"
+	}
+	return bound
+}
+
+// bindStructType is a set of type binders that convert Solidity tuple types to some supported
+// programming language struct definition.
+var bindStructType = map[Lang]func(kind abi.Type, structs map[string]*tmplStruct) string{
+	LangGo:   bindStructTypeGo,
+	LangJava: bindStructTypeJava,
+}
+
+// bindStructTypeGo converts a Solidity tuple type to a Go one and records the mapping
+// in the given map.
+// Notably, this function will resolve and record nested struct recursively.
+func bindStructTypeGo(kind abi.Type, structs map[string]*tmplStruct) string {
+	switch kind.T {
+	case abi.TupleTy:
+		if s, exist := structs[kind.String()]; exist {
+			return s.Name
+		}
+		var fields []*tmplField
+		for i, elem := range kind.TupleElems {
+			field := bindStructTypeGo(*elem, structs)
+			fields = append(fields, &tmplField{Type: field, Name: capitalise(kind.TupleRawNames[i]), SolKind: *elem})
+		}
+		name := fmt.Sprintf("Struct%d", len(structs))
+		structs[kind.String()] = &tmplStruct{
+			Name:   name,
+			Fields: fields,
+		}
+		return name
+	case abi.ArrayTy:
+		return fmt.Sprintf("[%d]", kind.Size) + bindStructTypeGo(*kind.Elem, structs)
+	case abi.SliceTy:
+		return "[]" + bindStructTypeGo(*kind.Elem, structs)
+	default:
+		return bindBasicTypeGo(kind)
+	}
+}
+
+// bindStructTypeJava converts a Solidity tuple type to a Java one and records the mapping
+// in the given map.
+// Notably, this function will resolve and record nested struct recursively.
+func bindStructTypeJava(kind abi.Type, structs map[string]*tmplStruct) string {
+	switch kind.T {
+	case abi.TupleTy:
+		if s, exist := structs[kind.String()]; exist {
+			return s.Name
+		}
+		var fields []*tmplField
+		for i, elem := range kind.TupleElems {
+			field := bindStructTypeJava(*elem, structs)
+			fields = append(fields, &tmplField{Type: field, Name: decapitalise(kind.TupleRawNames[i]), SolKind: *elem})
+		}
+		name := fmt.Sprintf("Class%d", len(structs))
+		structs[kind.String()] = &tmplStruct{
+			Name:   name,
+			Fields: fields,
+		}
+		return name
+	case abi.ArrayTy, abi.SliceTy:
+		return pluralizeJavaType(bindStructTypeJava(*kind.Elem, structs))
+	default:
+		return bindBasicTypeJava(kind)
+	}
+}
+
+// namedType is a set of functions that transform language specific types to
+// named versions that my be used inside method names.
+var namedType = map[Lang]func(string, abi.Type) string{
+	LangGo:   func(string, abi.Type) string { panic("this shouldn't be needed") },
+	LangJava: namedTypeJava,
+}
+
+// namedTypeJava converts some primitive data types to named variants that can
+// be used as parts of method names.
+func namedTypeJava(javaKind string, solKind abi.Type) string {
+	switch javaKind {
+	case "byte[]":
+		return "Binary"
+	case "boolean":
+		return "Bool"
+	default:
+		parts := regexp.MustCompile(`(u)?int([0-9]*)(\[[0-9]*\])?`).FindStringSubmatch(solKind.String())
+		if len(parts) != 4 {
+			return javaKind
+		}
+		switch parts[2] {
+		case "8", "16", "32", "64":
+			if parts[3] == "" {
+				return capitalise(fmt.Sprintf("%sint%s", parts[1], parts[2]))
+			}
+			return capitalise(fmt.Sprintf("%sint%ss", parts[1], parts[2]))
+
+		default:
+			return javaKind
+		}
+	}
+}
+
+// methodNormalizer is a name transformer that modifies Solidity method names to
+// conform to target language naming concentions.
+var methodNormalizer = map[Lang]func(string) string{
+	LangGo:   abi.ToCamelCase,
+	LangJava: decapitalise,
+}
+
+// capitalise makes a camel-case string which starts with an upper case character.
+func capitalise(input string) string {
+	return abi.ToCamelCase(input)
+}
+
+// decapitalise makes a camel-case string which starts with a lower case character.
+func decapitalise(input string) string {
+	if len(input) == 0 {
+		return input
+	}
+
+	goForm := abi.ToCamelCase(input)
+	return strings.ToLower(goForm[:1]) + goForm[1:]
+}
+
+// structured checks whether a list of ABI data types has enough information to
+// operate through a proper Go struct or if flat returns are needed.
+func structured(args abi.Arguments) bool {
+	if len(args) < 2 {
+		return false
+	}
+	exists := make(map[string]bool)
+	for _, out := range args {
+		// If the name is anonymous, we can't organize into a struct
+		if out.Name == "" {
+			return false
+		}
+		// If the field name is empty when normalized or collides (var, Var, _var, _Var),
+		// we can't organize into a struct
+		field := capitalise(out.Name)
+		if field == "" || exists[field] {
+			return false
+		}
+		exists[field] = true
+	}
+	return true
+}
+
+// resolveArgName converts a raw argument representation into a user friendly format.
+func resolveArgName(arg abi.Argument, structs map[string]*tmplStruct) string {
+	var (
+		prefix   string
+		embedded string
+		typ      = &arg.Type
+	)
+loop:
+	for {
+		switch typ.T {
+		case abi.SliceTy:
+			prefix += "[]"
+		case abi.ArrayTy:
+			prefix += fmt.Sprintf("[%d]", typ.Size)
+		default:
+			embedded = typ.String()
+			break loop
+		}
+		typ = typ.Elem
+	}
+	if s, exist := structs[embedded]; exist {
+		return prefix + s.Name
+	} else {
+		return arg.Type.String()
+	}
+}
+
+// formatMethod transforms raw method representation into a user friendly one.
+func formatMethod(method abi.Method, structs map[string]*tmplStruct) string {
+	inputs := make([]string, len(method.Inputs))
+	for i, input := range method.Inputs {
+		inputs[i] = fmt.Sprintf("%v %v", resolveArgName(input, structs), input.Name)
+	}
+	outputs := make([]string, len(method.Outputs))
+	for i, output := range method.Outputs {
+		outputs[i] = resolveArgName(output, structs)
+		if len(output.Name) > 0 {
+			outputs[i] += fmt.Sprintf(" %v", output.Name)
+		}
+	}
+	constant := ""
+	if method.Const {
+		constant = "constant "
+	}
+	return fmt.Sprintf("function %v(%v) %sreturns(%v)", method.RawName, strings.Join(inputs, ", "), constant, strings.Join(outputs, ", "))
+}
+
+// formatEvent transforms raw event representation into a user friendly one.
+func formatEvent(event abi.Event, structs map[string]*tmplStruct) string {
+	inputs := make([]string, len(event.Inputs))
+	for i, input := range event.Inputs {
+		if input.Indexed {
+			inputs[i] = fmt.Sprintf("%v indexed %v", resolveArgName(input, structs), input.Name)
+		} else {
+			inputs[i] = fmt.Sprintf("%v %v", resolveArgName(input, structs), input.Name)
+		}
+	}
+	return fmt.Sprintf("event %v(%v)", event.RawName, strings.Join(inputs, ", "))
+}
diff --git a/accounts/abi/bind/template.go b/accounts/abi/bind/template.go
new file mode 100644
index 0000000..e90d02e
--- /dev/null
+++ b/accounts/abi/bind/template.go
@@ -0,0 +1,616 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import "github.com/ava-labs/coreth/accounts/abi"
+
+// tmplData is the data structure required to fill the binding template.
+type tmplData struct {
+	Package   string                   // Name of the package to place the generated file in
+	Contracts map[string]*tmplContract // List of contracts to generate into this file
+	Libraries map[string]string        // Map the bytecode's link pattern to the library name
+}
+
+// tmplContract contains the data needed to generate an individual contract binding.
+type tmplContract struct {
+	Type        string                 // Type name of the main contract binding
+	InputABI    string                 // JSON ABI used as the input to generate the binding from
+	InputBin    string                 // Optional EVM bytecode used to denetare deploy code from
+	FuncSigs    map[string]string      // Optional map: string signature -> 4-byte signature
+	Constructor abi.Method             // Contract constructor for deploy parametrization
+	Calls       map[string]*tmplMethod // Contract calls that only read state data
+	Transacts   map[string]*tmplMethod // Contract calls that write state data
+	Events      map[string]*tmplEvent  // Contract events accessors
+	Libraries   map[string]string      // Same as tmplData, but filtered to only keep what the contract needs
+	Structs     map[string]*tmplStruct // Contract struct type definitions
+	Library     bool
+}
+
+// tmplMethod is a wrapper around an abi.Method that contains a few preprocessed
+// and cached data fields.
+type tmplMethod struct {
+	Original   abi.Method // Original method as parsed by the abi package
+	Normalized abi.Method // Normalized version of the parsed method (capitalized names, non-anonymous args/returns)
+	Structured bool       // Whether the returns should be accumulated into a struct
+}
+
+// tmplEvent is a wrapper around an a
+type tmplEvent struct {
+	Original   abi.Event // Original event as parsed by the abi package
+	Normalized abi.Event // Normalized version of the parsed fields
+}
+
+// tmplField is a wrapper around a struct field with binding language
+// struct type definition and relative filed name.
+type tmplField struct {
+	Type    string   // Field type representation depends on target binding language
+	Name    string   // Field name converted from the raw user-defined field name
+	SolKind abi.Type // Raw abi type information
+}
+
+// tmplStruct is a wrapper around an abi.tuple contains a auto-generated
+// struct name.
+type tmplStruct struct {
+	Name   string       // Auto-generated struct name(We can't obtain the raw struct name through abi)
+	Fields []*tmplField // Struct fields definition depends on the binding language.
+}
+
+// tmplSource is language to template mapping containing all the supported
+// programming languages the package can generate to.
+var tmplSource = map[Lang]string{
+	LangGo:   tmplSourceGo,
+	LangJava: tmplSourceJava,
+}
+
+// tmplSourceGo is the Go source template use to generate the contract binding
+// based on.
+const tmplSourceGo = `
+// Code generated - DO NOT EDIT.
+// This file is a generated binding and any manual changes will be lost.
+
+package {{.Package}}
+
+import (
+	"math/big"
+	"strings"
+
+	ethereum "github.com/ava-labs/go-ethereum"
+	"github.com/ava-labs/coreth/accounts/abi"
+	"github.com/ava-labs/coreth/accounts/abi/bind"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/coreth/core/types"
+	"github.com/ava-labs/go-ethereum/event"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var (
+	_ = big.NewInt
+	_ = strings.NewReader
+	_ = ethereum.NotFound
+	_ = abi.U256
+	_ = bind.Bind
+	_ = common.Big1
+	_ = types.BloomLookup
+	_ = event.NewSubscription
+)
+
+{{range $contract := .Contracts}}
+	{{$structs := $contract.Structs}}
+	// {{.Type}}ABI is the input ABI used to generate the binding from.
+	const {{.Type}}ABI = "{{.InputABI}}"
+
+	{{if $contract.FuncSigs}}
+		// {{.Type}}FuncSigs maps the 4-byte function signature to its string representation.
+		var {{.Type}}FuncSigs = map[string]string{
+			{{range $strsig, $binsig := .FuncSigs}}"{{$binsig}}": "{{$strsig}}",
+			{{end}}
+		}
+	{{end}}
+
+	{{if .InputBin}}
+		// {{.Type}}Bin is the compiled bytecode used for deploying new contracts.
+		var {{.Type}}Bin = "0x{{.InputBin}}"
+
+		// Deploy{{.Type}} deploys a new Ethereum contract, binding an instance of {{.Type}} to it.
+		func Deploy{{.Type}}(auth *bind.TransactOpts, backend bind.ContractBackend {{range .Constructor.Inputs}}, {{.Name}} {{bindtype .Type $structs}}{{end}}) (common.Address, *types.Transaction, *{{.Type}}, error) {
+		  parsed, err := abi.JSON(strings.NewReader({{.Type}}ABI))
+		  if err != nil {
+		    return common.Address{}, nil, nil, err
+		  }
+		  {{range $pattern, $name := .Libraries}}
+			{{decapitalise $name}}Addr, _, _, _ := Deploy{{capitalise $name}}(auth, backend)
+			{{$contract.Type}}Bin = strings.Replace({{$contract.Type}}Bin, "__${{$pattern}}$__", {{decapitalise $name}}Addr.String()[2:], -1)
+		  {{end}}
+		  address, tx, contract, err := bind.DeployContract(auth, parsed, common.FromHex({{.Type}}Bin), backend {{range .Constructor.Inputs}}, {{.Name}}{{end}})
+		  if err != nil {
+		    return common.Address{}, nil, nil, err
+		  }
+		  return address, tx, &{{.Type}}{ {{.Type}}Caller: {{.Type}}Caller{contract: contract}, {{.Type}}Transactor: {{.Type}}Transactor{contract: contract}, {{.Type}}Filterer: {{.Type}}Filterer{contract: contract} }, nil
+		}
+	{{end}}
+
+	// {{.Type}} is an auto generated Go binding around an Ethereum contract.
+	type {{.Type}} struct {
+	  {{.Type}}Caller     // Read-only binding to the contract
+	  {{.Type}}Transactor // Write-only binding to the contract
+	  {{.Type}}Filterer   // Log filterer for contract events
+	}
+
+	// {{.Type}}Caller is an auto generated read-only Go binding around an Ethereum contract.
+	type {{.Type}}Caller struct {
+	  contract *bind.BoundContract // Generic contract wrapper for the low level calls
+	}
+
+	// {{.Type}}Transactor is an auto generated write-only Go binding around an Ethereum contract.
+	type {{.Type}}Transactor struct {
+	  contract *bind.BoundContract // Generic contract wrapper for the low level calls
+	}
+
+	// {{.Type}}Filterer is an auto generated log filtering Go binding around an Ethereum contract events.
+	type {{.Type}}Filterer struct {
+	  contract *bind.BoundContract // Generic contract wrapper for the low level calls
+	}
+
+	// {{.Type}}Session is an auto generated Go binding around an Ethereum contract,
+	// with pre-set call and transact options.
+	type {{.Type}}Session struct {
+	  Contract     *{{.Type}}        // Generic contract binding to set the session for
+	  CallOpts     bind.CallOpts     // Call options to use throughout this session
+	  TransactOpts bind.TransactOpts // Transaction auth options to use throughout this session
+	}
+
+	// {{.Type}}CallerSession is an auto generated read-only Go binding around an Ethereum contract,
+	// with pre-set call options.
+	type {{.Type}}CallerSession struct {
+	  Contract *{{.Type}}Caller // Generic contract caller binding to set the session for
+	  CallOpts bind.CallOpts    // Call options to use throughout this session
+	}
+
+	// {{.Type}}TransactorSession is an auto generated write-only Go binding around an Ethereum contract,
+	// with pre-set transact options.
+	type {{.Type}}TransactorSession struct {
+	  Contract     *{{.Type}}Transactor // Generic contract transactor binding to set the session for
+	  TransactOpts bind.TransactOpts    // Transaction auth options to use throughout this session
+	}
+
+	// {{.Type}}Raw is an auto generated low-level Go binding around an Ethereum contract.
+	type {{.Type}}Raw struct {
+	  Contract *{{.Type}} // Generic contract binding to access the raw methods on
+	}
+
+	// {{.Type}}CallerRaw is an auto generated low-level read-only Go binding around an Ethereum contract.
+	type {{.Type}}CallerRaw struct {
+		Contract *{{.Type}}Caller // Generic read-only contract binding to access the raw methods on
+	}
+
+	// {{.Type}}TransactorRaw is an auto generated low-level write-only Go binding around an Ethereum contract.
+	type {{.Type}}TransactorRaw struct {
+		Contract *{{.Type}}Transactor // Generic write-only contract binding to access the raw methods on
+	}
+
+	// New{{.Type}} creates a new instance of {{.Type}}, bound to a specific deployed contract.
+	func New{{.Type}}(address common.Address, backend bind.ContractBackend) (*{{.Type}}, error) {
+	  contract, err := bind{{.Type}}(address, backend, backend, backend)
+	  if err != nil {
+	    return nil, err
+	  }
+	  return &{{.Type}}{ {{.Type}}Caller: {{.Type}}Caller{contract: contract}, {{.Type}}Transactor: {{.Type}}Transactor{contract: contract}, {{.Type}}Filterer: {{.Type}}Filterer{contract: contract} }, nil
+	}
+
+	// New{{.Type}}Caller creates a new read-only instance of {{.Type}}, bound to a specific deployed contract.
+	func New{{.Type}}Caller(address common.Address, caller bind.ContractCaller) (*{{.Type}}Caller, error) {
+	  contract, err := bind{{.Type}}(address, caller, nil, nil)
+	  if err != nil {
+	    return nil, err
+	  }
+	  return &{{.Type}}Caller{contract: contract}, nil
+	}
+
+	// New{{.Type}}Transactor creates a new write-only instance of {{.Type}}, bound to a specific deployed contract.
+	func New{{.Type}}Transactor(address common.Address, transactor bind.ContractTransactor) (*{{.Type}}Transactor, error) {
+	  contract, err := bind{{.Type}}(address, nil, transactor, nil)
+	  if err != nil {
+	    return nil, err
+	  }
+	  return &{{.Type}}Transactor{contract: contract}, nil
+	}
+
+	// New{{.Type}}Filterer creates a new log filterer instance of {{.Type}}, bound to a specific deployed contract.
+ 	func New{{.Type}}Filterer(address common.Address, filterer bind.ContractFilterer) (*{{.Type}}Filterer, error) {
+ 	  contract, err := bind{{.Type}}(address, nil, nil, filterer)
+ 	  if err != nil {
+ 	    return nil, err
+ 	  }
+ 	  return &{{.Type}}Filterer{contract: contract}, nil
+ 	}
+
+	// bind{{.Type}} binds a generic wrapper to an already deployed contract.
+	func bind{{.Type}}(address common.Address, caller bind.ContractCaller, transactor bind.ContractTransactor, filterer bind.ContractFilterer) (*bind.BoundContract, error) {
+	  parsed, err := abi.JSON(strings.NewReader({{.Type}}ABI))
+	  if err != nil {
+	    return nil, err
+	  }
+	  return bind.NewBoundContract(address, parsed, caller, transactor, filterer), nil
+	}
+
+	// Call invokes the (constant) contract method with params as input values and
+	// sets the output to result. The result type might be a single field for simple
+	// returns, a slice of interfaces for anonymous returns and a struct for named
+	// returns.
+	func (_{{$contract.Type}} *{{$contract.Type}}Raw) Call(opts *bind.CallOpts, result interface{}, method string, params ...interface{}) error {
+		return _{{$contract.Type}}.Contract.{{$contract.Type}}Caller.contract.Call(opts, result, method, params...)
+	}
+
+	// Transfer initiates a plain transaction to move funds to the contract, calling
+	// its default method if one is available.
+	func (_{{$contract.Type}} *{{$contract.Type}}Raw) Transfer(opts *bind.TransactOpts) (*types.Transaction, error) {
+		return _{{$contract.Type}}.Contract.{{$contract.Type}}Transactor.contract.Transfer(opts)
+	}
+
+	// Transact invokes the (paid) contract method with params as input values.
+	func (_{{$contract.Type}} *{{$contract.Type}}Raw) Transact(opts *bind.TransactOpts, method string, params ...interface{}) (*types.Transaction, error) {
+		return _{{$contract.Type}}.Contract.{{$contract.Type}}Transactor.contract.Transact(opts, method, params...)
+	}
+
+	// Call invokes the (constant) contract method with params as input values and
+	// sets the output to result. The result type might be a single field for simple
+	// returns, a slice of interfaces for anonymous returns and a struct for named
+	// returns.
+	func (_{{$contract.Type}} *{{$contract.Type}}CallerRaw) Call(opts *bind.CallOpts, result interface{}, method string, params ...interface{}) error {
+		return _{{$contract.Type}}.Contract.contract.Call(opts, result, method, params...)
+	}
+
+	// Transfer initiates a plain transaction to move funds to the contract, calling
+	// its default method if one is available.
+	func (_{{$contract.Type}} *{{$contract.Type}}TransactorRaw) Transfer(opts *bind.TransactOpts) (*types.Transaction, error) {
+		return _{{$contract.Type}}.Contract.contract.Transfer(opts)
+	}
+
+	// Transact invokes the (paid) contract method with params as input values.
+	func (_{{$contract.Type}} *{{$contract.Type}}TransactorRaw) Transact(opts *bind.TransactOpts, method string, params ...interface{}) (*types.Transaction, error) {
+		return _{{$contract.Type}}.Contract.contract.Transact(opts, method, params...)
+	}
+
+	{{range .Structs}}
+		// {{.Name}} is an auto generated low-level Go binding around an user-defined struct.
+		type {{.Name}} struct {
+		{{range $field := .Fields}}
+		{{$field.Name}} {{$field.Type}}{{end}}
+		}
+	{{end}}
+
+	{{range .Calls}}
+		// {{.Normalized.Name}} is a free data retrieval call binding the contract method 0x{{printf "%x" .Original.ID}}.
+		//
+		// Solidity: {{formatmethod .Original $structs}}
+		func (_{{$contract.Type}} *{{$contract.Type}}Caller) {{.Normalized.Name}}(opts *bind.CallOpts {{range .Normalized.Inputs}}, {{.Name}} {{bindtype .Type $structs}} {{end}}) ({{if .Structured}}struct{ {{range .Normalized.Outputs}}{{.Name}} {{bindtype .Type $structs}};{{end}} },{{else}}{{range .Normalized.Outputs}}{{bindtype .Type $structs}},{{end}}{{end}} error) {
+			{{if .Structured}}ret := new(struct{
+				{{range .Normalized.Outputs}}{{.Name}} {{bindtype .Type $structs}}
+				{{end}}
+			}){{else}}var (
+				{{range $i, $_ := .Normalized.Outputs}}ret{{$i}} = new({{bindtype .Type $structs}})
+				{{end}}
+			){{end}}
+			out := {{if .Structured}}ret{{else}}{{if eq (len .Normalized.Outputs) 1}}ret0{{else}}&[]interface{}{
+				{{range $i, $_ := .Normalized.Outputs}}ret{{$i}},
+				{{end}}
+			}{{end}}{{end}}
+			err := _{{$contract.Type}}.contract.Call(opts, out, "{{.Original.Name}}" {{range .Normalized.Inputs}}, {{.Name}}{{end}})
+			return {{if .Structured}}*ret,{{else}}{{range $i, $_ := .Normalized.Outputs}}*ret{{$i}},{{end}}{{end}} err
+		}
+
+		// {{.Normalized.Name}} is a free data retrieval call binding the contract method 0x{{printf "%x" .Original.ID}}.
+		//
+		// Solidity: {{formatmethod .Original $structs}}
+		func (_{{$contract.Type}} *{{$contract.Type}}Session) {{.Normalized.Name}}({{range $i, $_ := .Normalized.Inputs}}{{if ne $i 0}},{{end}} {{.Name}} {{bindtype .Type $structs}} {{end}}) ({{if .Structured}}struct{ {{range .Normalized.Outputs}}{{.Name}} {{bindtype .Type $structs}};{{end}} }, {{else}} {{range .Normalized.Outputs}}{{bindtype .Type $structs}},{{end}} {{end}} error) {
+		  return _{{$contract.Type}}.Contract.{{.Normalized.Name}}(&_{{$contract.Type}}.CallOpts {{range .Normalized.Inputs}}, {{.Name}}{{end}})
+		}
+
+		// {{.Normalized.Name}} is a free data retrieval call binding the contract method 0x{{printf "%x" .Original.ID}}.
+		//
+		// Solidity: {{formatmethod .Original $structs}}
+		func (_{{$contract.Type}} *{{$contract.Type}}CallerSession) {{.Normalized.Name}}({{range $i, $_ := .Normalized.Inputs}}{{if ne $i 0}},{{end}} {{.Name}} {{bindtype .Type $structs}} {{end}}) ({{if .Structured}}struct{ {{range .Normalized.Outputs}}{{.Name}} {{bindtype .Type $structs}};{{end}} }, {{else}} {{range .Normalized.Outputs}}{{bindtype .Type $structs}},{{end}} {{end}} error) {
+		  return _{{$contract.Type}}.Contract.{{.Normalized.Name}}(&_{{$contract.Type}}.CallOpts {{range .Normalized.Inputs}}, {{.Name}}{{end}})
+		}
+	{{end}}
+
+	{{range .Transacts}}
+		// {{.Normalized.Name}} is a paid mutator transaction binding the contract method 0x{{printf "%x" .Original.ID}}.
+		//
+		// Solidity: {{formatmethod .Original $structs}}
+		func (_{{$contract.Type}} *{{$contract.Type}}Transactor) {{.Normalized.Name}}(opts *bind.TransactOpts {{range .Normalized.Inputs}}, {{.Name}} {{bindtype .Type $structs}} {{end}}) (*types.Transaction, error) {
+			return _{{$contract.Type}}.contract.Transact(opts, "{{.Original.Name}}" {{range .Normalized.Inputs}}, {{.Name}}{{end}})
+		}
+
+		// {{.Normalized.Name}} is a paid mutator transaction binding the contract method 0x{{printf "%x" .Original.ID}}.
+		//
+		// Solidity: {{formatmethod .Original $structs}}
+		func (_{{$contract.Type}} *{{$contract.Type}}Session) {{.Normalized.Name}}({{range $i, $_ := .Normalized.Inputs}}{{if ne $i 0}},{{end}} {{.Name}} {{bindtype .Type $structs}} {{end}}) (*types.Transaction, error) {
+		  return _{{$contract.Type}}.Contract.{{.Normalized.Name}}(&_{{$contract.Type}}.TransactOpts {{range $i, $_ := .Normalized.Inputs}}, {{.Name}}{{end}})
+		}
+
+		// {{.Normalized.Name}} is a paid mutator transaction binding the contract method 0x{{printf "%x" .Original.ID}}.
+		//
+		// Solidity: {{formatmethod .Original $structs}}
+		func (_{{$contract.Type}} *{{$contract.Type}}TransactorSession) {{.Normalized.Name}}({{range $i, $_ := .Normalized.Inputs}}{{if ne $i 0}},{{end}} {{.Name}} {{bindtype .Type $structs}} {{end}}) (*types.Transaction, error) {
+		  return _{{$contract.Type}}.Contract.{{.Normalized.Name}}(&_{{$contract.Type}}.TransactOpts {{range $i, $_ := .Normalized.Inputs}}, {{.Name}}{{end}})
+		}
+	{{end}}
+
+	{{range .Events}}
+		// {{$contract.Type}}{{.Normalized.Name}}Iterator is returned from Filter{{.Normalized.Name}} and is used to iterate over the raw logs and unpacked data for {{.Normalized.Name}} events raised by the {{$contract.Type}} contract.
+		type {{$contract.Type}}{{.Normalized.Name}}Iterator struct {
+			Event *{{$contract.Type}}{{.Normalized.Name}} // Event containing the contract specifics and raw log
+
+			contract *bind.BoundContract // Generic contract to use for unpacking event data
+			event    string              // Event name to use for unpacking event data
+
+			logs chan types.Log        // Log channel receiving the found contract events
+			sub  ethereum.Subscription // Subscription for errors, completion and termination
+			done bool                  // Whether the subscription completed delivering logs
+			fail error                 // Occurred error to stop iteration
+		}
+		// Next advances the iterator to the subsequent event, returning whether there
+		// are any more events found. In case of a retrieval or parsing error, false is
+		// returned and Error() can be queried for the exact failure.
+		func (it *{{$contract.Type}}{{.Normalized.Name}}Iterator) Next() bool {
+			// If the iterator failed, stop iterating
+			if (it.fail != nil) {
+				return false
+			}
+			// If the iterator completed, deliver directly whatever's available
+			if (it.done) {
+				select {
+				case log := <-it.logs:
+					it.Event = new({{$contract.Type}}{{.Normalized.Name}})
+					if err := it.contract.UnpackLog(it.Event, it.event, log); err != nil {
+						it.fail = err
+						return false
+					}
+					it.Event.Raw = log
+					return true
+
+				default:
+					return false
+				}
+			}
+			// Iterator still in progress, wait for either a data or an error event
+			select {
+			case log := <-it.logs:
+				it.Event = new({{$contract.Type}}{{.Normalized.Name}})
+				if err := it.contract.UnpackLog(it.Event, it.event, log); err != nil {
+					it.fail = err
+					return false
+				}
+				it.Event.Raw = log
+				return true
+
+			case err := <-it.sub.Err():
+				it.done = true
+				it.fail = err
+				return it.Next()
+			}
+		}
+		// Error returns any retrieval or parsing error occurred during filtering.
+		func (it *{{$contract.Type}}{{.Normalized.Name}}Iterator) Error() error {
+			return it.fail
+		}
+		// Close terminates the iteration process, releasing any pending underlying
+		// resources.
+		func (it *{{$contract.Type}}{{.Normalized.Name}}Iterator) Close() error {
+			it.sub.Unsubscribe()
+			return nil
+		}
+
+		// {{$contract.Type}}{{.Normalized.Name}} represents a {{.Normalized.Name}} event raised by the {{$contract.Type}} contract.
+		type {{$contract.Type}}{{.Normalized.Name}} struct { {{range .Normalized.Inputs}}
+			{{capitalise .Name}} {{if .Indexed}}{{bindtopictype .Type $structs}}{{else}}{{bindtype .Type $structs}}{{end}}; {{end}}
+			Raw types.Log // Blockchain specific contextual infos
+		}
+
+		// Filter{{.Normalized.Name}} is a free log retrieval operation binding the contract event 0x{{printf "%x" .Original.ID}}.
+		//
+		// Solidity: {{formatevent .Original $structs}}
+ 		func (_{{$contract.Type}} *{{$contract.Type}}Filterer) Filter{{.Normalized.Name}}(opts *bind.FilterOpts{{range .Normalized.Inputs}}{{if .Indexed}}, {{.Name}} []{{bindtype .Type $structs}}{{end}}{{end}}) (*{{$contract.Type}}{{.Normalized.Name}}Iterator, error) {
+			{{range .Normalized.Inputs}}
+			{{if .Indexed}}var {{.Name}}Rule []interface{}
+			for _, {{.Name}}Item := range {{.Name}} {
+				{{.Name}}Rule = append({{.Name}}Rule, {{.Name}}Item)
+			}{{end}}{{end}}
+
+			logs, sub, err := _{{$contract.Type}}.contract.FilterLogs(opts, "{{.Original.Name}}"{{range .Normalized.Inputs}}{{if .Indexed}}, {{.Name}}Rule{{end}}{{end}})
+			if err != nil {
+				return nil, err
+			}
+			return &{{$contract.Type}}{{.Normalized.Name}}Iterator{contract: _{{$contract.Type}}.contract, event: "{{.Original.Name}}", logs: logs, sub: sub}, nil
+ 		}
+
+		// Watch{{.Normalized.Name}} is a free log subscription operation binding the contract event 0x{{printf "%x" .Original.ID}}.
+		//
+		// Solidity: {{formatevent .Original $structs}}
+		func (_{{$contract.Type}} *{{$contract.Type}}Filterer) Watch{{.Normalized.Name}}(opts *bind.WatchOpts, sink chan<- *{{$contract.Type}}{{.Normalized.Name}}{{range .Normalized.Inputs}}{{if .Indexed}}, {{.Name}} []{{bindtype .Type $structs}}{{end}}{{end}}) (event.Subscription, error) {
+			{{range .Normalized.Inputs}}
+			{{if .Indexed}}var {{.Name}}Rule []interface{}
+			for _, {{.Name}}Item := range {{.Name}} {
+				{{.Name}}Rule = append({{.Name}}Rule, {{.Name}}Item)
+			}{{end}}{{end}}
+
+			logs, sub, err := _{{$contract.Type}}.contract.WatchLogs(opts, "{{.Original.Name}}"{{range .Normalized.Inputs}}{{if .Indexed}}, {{.Name}}Rule{{end}}{{end}})
+			if err != nil {
+				return nil, err
+			}
+			return event.NewSubscription(func(quit <-chan struct{}) error {
+				defer sub.Unsubscribe()
+				for {
+					select {
+					case log := <-logs:
+						// New log arrived, parse the event and forward to the user
+						event := new({{$contract.Type}}{{.Normalized.Name}})
+						if err := _{{$contract.Type}}.contract.UnpackLog(event, "{{.Original.Name}}", log); err != nil {
+							return err
+						}
+						event.Raw = log
+
+						select {
+						case sink <- event:
+						case err := <-sub.Err():
+							return err
+						case <-quit:
+							return nil
+						}
+					case err := <-sub.Err():
+						return err
+					case <-quit:
+						return nil
+					}
+				}
+			}), nil
+		}
+
+		// Parse{{.Normalized.Name}} is a log parse operation binding the contract event 0x{{printf "%x" .Original.ID}}.
+		//
+		// Solidity: {{.Original.String}}
+		func (_{{$contract.Type}} *{{$contract.Type}}Filterer) Parse{{.Normalized.Name}}(log types.Log) (*{{$contract.Type}}{{.Normalized.Name}}, error) {
+			event := new({{$contract.Type}}{{.Normalized.Name}})
+			if err := _{{$contract.Type}}.contract.UnpackLog(event, "{{.Original.Name}}", log); err != nil {
+				return nil, err
+			}
+			return event, nil
+		}
+
+ 	{{end}}
+{{end}}
+`
+
+// tmplSourceJava is the Java source template use to generate the contract binding
+// based on.
+const tmplSourceJava = `
+// This file is an automatically generated Java binding. Do not modify as any
+// change will likely be lost upon the next re-generation!
+
+package {{.Package}};
+
+import org.ethereum.geth.*;
+import java.util.*;
+
+{{range $contract := .Contracts}}
+{{$structs := $contract.Structs}}
+{{if not .Library}}public {{end}}class {{.Type}} {
+	// ABI is the input ABI used to generate the binding from.
+	public final static String ABI = "{{.InputABI}}";
+	{{if $contract.FuncSigs}}
+		// {{.Type}}FuncSigs maps the 4-byte function signature to its string representation.
+		public final static Map<String, String> {{.Type}}FuncSigs;
+		static {
+			Hashtable<String, String> temp = new Hashtable<String, String>();
+			{{range $strsig, $binsig := .FuncSigs}}temp.put("{{$binsig}}", "{{$strsig}}");
+			{{end}}
+			{{.Type}}FuncSigs = Collections.unmodifiableMap(temp);
+		}
+	{{end}}
+	{{if .InputBin}}
+	// BYTECODE is the compiled bytecode used for deploying new contracts.
+	public final static String BYTECODE = "0x{{.InputBin}}";
+
+	// deploy deploys a new Ethereum contract, binding an instance of {{.Type}} to it.
+	public static {{.Type}} deploy(TransactOpts auth, EthereumClient client{{range .Constructor.Inputs}}, {{bindtype .Type $structs}} {{.Name}}{{end}}) throws Exception {
+		Interfaces args = Geth.newInterfaces({{(len .Constructor.Inputs)}});
+		String bytecode = BYTECODE;
+		{{if .Libraries}}
+
+		// "link" contract to dependent libraries by deploying them first.
+		{{range $pattern, $name := .Libraries}}
+		{{capitalise $name}} {{decapitalise $name}}Inst = {{capitalise $name}}.deploy(auth, client);
+		bytecode = bytecode.replace("__${{$pattern}}$__", {{decapitalise $name}}Inst.Address.getHex().substring(2));
+		{{end}}
+		{{end}}
+		{{range $index, $element := .Constructor.Inputs}}Interface arg{{$index}} = Geth.newInterface();arg{{$index}}.set{{namedtype (bindtype .Type $structs) .Type}}({{.Name}});args.set({{$index}},arg{{$index}});
+		{{end}}
+		return new {{.Type}}(Geth.deployContract(auth, ABI, Geth.decodeFromHex(bytecode), client, args));
+	}
+
+	// Internal constructor used by contract deployment.
+	private {{.Type}}(BoundContract deployment) {
+		this.Address  = deployment.getAddress();
+		this.Deployer = deployment.getDeployer();
+		this.Contract = deployment;
+	}
+	{{end}}
+
+	// Ethereum address where this contract is located at.
+	public final Address Address;
+
+	// Ethereum transaction in which this contract was deployed (if known!).
+	public final Transaction Deployer;
+
+	// Contract instance bound to a blockchain address.
+	private final BoundContract Contract;
+
+	// Creates a new instance of {{.Type}}, bound to a specific deployed contract.
+	public {{.Type}}(Address address, EthereumClient client) throws Exception {
+		this(Geth.bindContract(address, ABI, client));
+	}
+
+	{{range .Calls}}
+	{{if gt (len .Normalized.Outputs) 1}}
+	// {{capitalise .Normalized.Name}}Results is the output of a call to {{.Normalized.Name}}.
+	public class {{capitalise .Normalized.Name}}Results {
+		{{range $index, $item := .Normalized.Outputs}}public {{bindtype .Type $structs}} {{if ne .Name ""}}{{.Name}}{{else}}Return{{$index}}{{end}};
+		{{end}}
+	}
+	{{end}}
+
+	// {{.Normalized.Name}} is a free data retrieval call binding the contract method 0x{{printf "%x" .Original.ID}}.
+	//
+	// Solidity: {{.Original.String}}
+	public {{if gt (len .Normalized.Outputs) 1}}{{capitalise .Normalized.Name}}Results{{else}}{{range .Normalized.Outputs}}{{bindtype .Type $structs}}{{end}}{{end}} {{.Normalized.Name}}(CallOpts opts{{range .Normalized.Inputs}}, {{bindtype .Type $structs}} {{.Name}}{{end}}) throws Exception {
+		Interfaces args = Geth.newInterfaces({{(len .Normalized.Inputs)}});
+		{{range $index, $item := .Normalized.Inputs}}Interface arg{{$index}} = Geth.newInterface();arg{{$index}}.set{{namedtype (bindtype .Type $structs) .Type}}({{.Name}});args.set({{$index}},arg{{$index}});
+		{{end}}
+
+		Interfaces results = Geth.newInterfaces({{(len .Normalized.Outputs)}});
+		{{range $index, $item := .Normalized.Outputs}}Interface result{{$index}} = Geth.newInterface(); result{{$index}}.setDefault{{namedtype (bindtype .Type $structs) .Type}}(); results.set({{$index}}, result{{$index}});
+		{{end}}
+
+		if (opts == null) {
+			opts = Geth.newCallOpts();
+		}
+		this.Contract.call(opts, results, "{{.Original.Name}}", args);
+		{{if gt (len .Normalized.Outputs) 1}}
+			{{capitalise .Normalized.Name}}Results result = new {{capitalise .Normalized.Name}}Results();
+			{{range $index, $item := .Normalized.Outputs}}result.{{if ne .Name ""}}{{.Name}}{{else}}Return{{$index}}{{end}} = results.get({{$index}}).get{{namedtype (bindtype .Type $structs) .Type}}();
+			{{end}}
+			return result;
+		{{else}}{{range .Normalized.Outputs}}return results.get(0).get{{namedtype (bindtype .Type $structs) .Type}}();{{end}}
+		{{end}}
+	}
+	{{end}}
+
+	{{range .Transacts}}
+	// {{.Normalized.Name}} is a paid mutator transaction binding the contract method 0x{{printf "%x" .Original.ID}}.
+	//
+	// Solidity: {{.Original.String}}
+	public Transaction {{.Normalized.Name}}(TransactOpts opts{{range .Normalized.Inputs}}, {{bindtype .Type $structs}} {{.Name}}{{end}}) throws Exception {
+		Interfaces args = Geth.newInterfaces({{(len .Normalized.Inputs)}});
+		{{range $index, $item := .Normalized.Inputs}}Interface arg{{$index}} = Geth.newInterface();arg{{$index}}.set{{namedtype (bindtype .Type $structs) .Type}}({{.Name}});args.set({{$index}},arg{{$index}});
+		{{end}}
+		return this.Contract.transact(opts, "{{.Original.Name}}"	, args);
+	}
+	{{end}}
+}
+{{end}}
+`
diff --git a/accounts/abi/bind/topics.go b/accounts/abi/bind/topics.go
new file mode 100644
index 0000000..58e4ff3
--- /dev/null
+++ b/accounts/abi/bind/topics.go
@@ -0,0 +1,241 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"math/big"
+	"reflect"
+
+	"github.com/ava-labs/coreth/accounts/abi"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/crypto"
+)
+
+// makeTopics converts a filter query argument list into a filter topic set.
+func makeTopics(query ...[]interface{}) ([][]common.Hash, error) {
+	topics := make([][]common.Hash, len(query))
+	for i, filter := range query {
+		for _, rule := range filter {
+			var topic common.Hash
+
+			// Try to generate the topic based on simple types
+			switch rule := rule.(type) {
+			case common.Hash:
+				copy(topic[:], rule[:])
+			case common.Address:
+				copy(topic[common.HashLength-common.AddressLength:], rule[:])
+			case *big.Int:
+				blob := rule.Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case bool:
+				if rule {
+					topic[common.HashLength-1] = 1
+				}
+			case int8:
+				blob := big.NewInt(int64(rule)).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case int16:
+				blob := big.NewInt(int64(rule)).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case int32:
+				blob := big.NewInt(int64(rule)).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case int64:
+				blob := big.NewInt(rule).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case uint8:
+				blob := new(big.Int).SetUint64(uint64(rule)).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case uint16:
+				blob := new(big.Int).SetUint64(uint64(rule)).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case uint32:
+				blob := new(big.Int).SetUint64(uint64(rule)).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case uint64:
+				blob := new(big.Int).SetUint64(rule).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case string:
+				hash := crypto.Keccak256Hash([]byte(rule))
+				copy(topic[:], hash[:])
+			case []byte:
+				hash := crypto.Keccak256Hash(rule)
+				copy(topic[:], hash[:])
+
+			default:
+				// Attempt to generate the topic from funky types
+				val := reflect.ValueOf(rule)
+
+				switch {
+
+				// static byte array
+				case val.Kind() == reflect.Array && reflect.TypeOf(rule).Elem().Kind() == reflect.Uint8:
+					reflect.Copy(reflect.ValueOf(topic[:val.Len()]), val)
+
+				default:
+					return nil, fmt.Errorf("unsupported indexed type: %T", rule)
+				}
+			}
+			topics[i] = append(topics[i], topic)
+		}
+	}
+	return topics, nil
+}
+
+// Big batch of reflect types for topic reconstruction.
+var (
+	reflectHash    = reflect.TypeOf(common.Hash{})
+	reflectAddress = reflect.TypeOf(common.Address{})
+	reflectBigInt  = reflect.TypeOf(new(big.Int))
+)
+
+// parseTopics converts the indexed topic fields into actual log field values.
+//
+// Note, dynamic types cannot be reconstructed since they get mapped to Keccak256
+// hashes as the topic value!
+func parseTopics(out interface{}, fields abi.Arguments, topics []common.Hash) error {
+	// Sanity check that the fields and topics match up
+	if len(fields) != len(topics) {
+		return errors.New("topic/field count mismatch")
+	}
+	// Iterate over all the fields and reconstruct them from topics
+	for _, arg := range fields {
+		if !arg.Indexed {
+			return errors.New("non-indexed field in topic reconstruction")
+		}
+		field := reflect.ValueOf(out).Elem().FieldByName(capitalise(arg.Name))
+
+		// Try to parse the topic back into the fields based on primitive types
+		switch field.Kind() {
+		case reflect.Bool:
+			if topics[0][common.HashLength-1] == 1 {
+				field.Set(reflect.ValueOf(true))
+			}
+		case reflect.Int8:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(int8(num.Int64())))
+
+		case reflect.Int16:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(int16(num.Int64())))
+
+		case reflect.Int32:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(int32(num.Int64())))
+
+		case reflect.Int64:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(num.Int64()))
+
+		case reflect.Uint8:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(uint8(num.Uint64())))
+
+		case reflect.Uint16:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(uint16(num.Uint64())))
+
+		case reflect.Uint32:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(uint32(num.Uint64())))
+
+		case reflect.Uint64:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(num.Uint64()))
+
+		default:
+			// Ran out of plain primitive types, try custom types
+			switch field.Type() {
+			case reflectHash: // Also covers all dynamic types
+				field.Set(reflect.ValueOf(topics[0]))
+
+			case reflectAddress:
+				var addr common.Address
+				copy(addr[:], topics[0][common.HashLength-common.AddressLength:])
+				field.Set(reflect.ValueOf(addr))
+
+			case reflectBigInt:
+				num := new(big.Int).SetBytes(topics[0][:])
+				field.Set(reflect.ValueOf(num))
+
+			default:
+				// Ran out of custom types, try the crazies
+				switch {
+
+				// static byte array
+				case arg.Type.T == abi.FixedBytesTy:
+					reflect.Copy(field, reflect.ValueOf(topics[0][:arg.Type.Size]))
+
+				default:
+					return fmt.Errorf("unsupported indexed type: %v", arg.Type)
+				}
+			}
+		}
+		topics = topics[1:]
+	}
+	return nil
+}
+
+// parseTopicsIntoMap converts the indexed topic field-value pairs into map key-value pairs
+func parseTopicsIntoMap(out map[string]interface{}, fields abi.Arguments, topics []common.Hash) error {
+	// Sanity check that the fields and topics match up
+	if len(fields) != len(topics) {
+		return errors.New("topic/field count mismatch")
+	}
+	// Iterate over all the fields and reconstruct them from topics
+	for _, arg := range fields {
+		if !arg.Indexed {
+			return errors.New("non-indexed field in topic reconstruction")
+		}
+
+		switch arg.Type.T {
+		case abi.BoolTy:
+			out[arg.Name] = topics[0][common.HashLength-1] == 1
+		case abi.IntTy, abi.UintTy:
+			num := new(big.Int).SetBytes(topics[0][:])
+			out[arg.Name] = num
+		case abi.AddressTy:
+			var addr common.Address
+			copy(addr[:], topics[0][common.HashLength-common.AddressLength:])
+			out[arg.Name] = addr
+		case abi.HashTy:
+			out[arg.Name] = topics[0]
+		case abi.FixedBytesTy:
+			out[arg.Name] = topics[0][:]
+		case abi.StringTy, abi.BytesTy, abi.SliceTy, abi.ArrayTy:
+			// Array types (including strings and bytes) have their keccak256 hashes stored in the topic- not a hash
+			// whose bytes can be decoded to the actual value- so the best we can do is retrieve that hash
+			out[arg.Name] = topics[0]
+		case abi.FunctionTy:
+			if garbage := binary.BigEndian.Uint64(topics[0][0:8]); garbage != 0 {
+				return fmt.Errorf("bind: got improperly encoded function type, got %v", topics[0].Bytes())
+			}
+			var tmp [24]byte
+			copy(tmp[:], topics[0][8:32])
+			out[arg.Name] = tmp
+		default: // Not handling tuples
+			return fmt.Errorf("unsupported indexed type: %v", arg.Type)
+		}
+
+		topics = topics[1:]
+	}
+
+	return nil
+}
diff --git a/accounts/abi/bind/util.go b/accounts/abi/bind/util.go
new file mode 100644
index 0000000..b3ec22c
--- /dev/null
+++ b/accounts/abi/bind/util.go
@@ -0,0 +1,76 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/ava-labs/coreth/core/types"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/log"
+)
+
+// WaitMined waits for tx to be mined on the blockchain.
+// It stops waiting when the context is canceled.
+func WaitMined(ctx context.Context, b DeployBackend, tx *types.Transaction) (*types.Receipt, error) {
+	queryTicker := time.NewTicker(time.Second)
+	defer queryTicker.Stop()
+
+	logger := log.New("hash", tx.Hash())
+	for {
+		receipt, err := b.TransactionReceipt(ctx, tx.Hash())
+		if receipt != nil {
+			return receipt, nil
+		}
+		if err != nil {
+			logger.Trace("Receipt retrieval failed", "err", err)
+		} else {
+			logger.Trace("Transaction not yet mined")
+		}
+		// Wait for the next round.
+		select {
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		case <-queryTicker.C:
+		}
+	}
+}
+
+// WaitDeployed waits for a contract deployment transaction and returns the on-chain
+// contract address when it is mined. It stops waiting when ctx is canceled.
+func WaitDeployed(ctx context.Context, b DeployBackend, tx *types.Transaction) (common.Address, error) {
+	if tx.To() != nil {
+		return common.Address{}, fmt.Errorf("tx is not contract creation")
+	}
+	receipt, err := WaitMined(ctx, b, tx)
+	if err != nil {
+		return common.Address{}, err
+	}
+	if receipt.ContractAddress == (common.Address{}) {
+		return common.Address{}, fmt.Errorf("zero address")
+	}
+	// Check that code has indeed been deployed at the address.
+	// This matters on pre-Homestead chains: OOG in the constructor
+	// could leave an empty account behind.
+	code, err := b.CodeAt(ctx, receipt.ContractAddress, nil)
+	if err == nil && len(code) == 0 {
+		err = ErrNoCodeAfterDeploy
+	}
+	return receipt.ContractAddress, err
+}
diff --git a/accounts/abi/doc.go b/accounts/abi/doc.go
new file mode 100644
index 0000000..8242068
--- /dev/null
+++ b/accounts/abi/doc.go
@@ -0,0 +1,26 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package abi implements the Ethereum ABI (Application Binary
+// Interface).
+//
+// The Ethereum ABI is strongly typed, known at compile time
+// and static. This ABI will handle basic type casting; unsigned
+// to signed and visa versa. It does not handle slice casting such
+// as unsigned slice to signed slice. Bit size type casting is also
+// handled. ints with a bit size of 32 will be properly cast to int256,
+// etc.
+package abi
diff --git a/accounts/abi/error.go b/accounts/abi/error.go
new file mode 100644
index 0000000..9d8674a
--- /dev/null
+++ b/accounts/abi/error.go
@@ -0,0 +1,84 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+)
+
+var (
+	errBadBool = errors.New("abi: improperly encoded boolean value")
+)
+
+// formatSliceString formats the reflection kind with the given slice size
+// and returns a formatted string representation.
+func formatSliceString(kind reflect.Kind, sliceSize int) string {
+	if sliceSize == -1 {
+		return fmt.Sprintf("[]%v", kind)
+	}
+	return fmt.Sprintf("[%d]%v", sliceSize, kind)
+}
+
+// sliceTypeCheck checks that the given slice can by assigned to the reflection
+// type in t.
+func sliceTypeCheck(t Type, val reflect.Value) error {
+	if val.Kind() != reflect.Slice && val.Kind() != reflect.Array {
+		return typeErr(formatSliceString(t.Kind, t.Size), val.Type())
+	}
+
+	if t.T == ArrayTy && val.Len() != t.Size {
+		return typeErr(formatSliceString(t.Elem.Kind, t.Size), formatSliceString(val.Type().Elem().Kind(), val.Len()))
+	}
+
+	if t.Elem.T == SliceTy {
+		if val.Len() > 0 {
+			return sliceTypeCheck(*t.Elem, val.Index(0))
+		}
+	} else if t.Elem.T == ArrayTy {
+		return sliceTypeCheck(*t.Elem, val.Index(0))
+	}
+
+	if elemKind := val.Type().Elem().Kind(); elemKind != t.Elem.Kind {
+		return typeErr(formatSliceString(t.Elem.Kind, t.Size), val.Type())
+	}
+	return nil
+}
+
+// typeCheck checks that the given reflection value can be assigned to the reflection
+// type in t.
+func typeCheck(t Type, value reflect.Value) error {
+	if t.T == SliceTy || t.T == ArrayTy {
+		return sliceTypeCheck(t, value)
+	}
+
+	// Check base type validity. Element types will be checked later on.
+	if t.Kind != value.Kind() {
+		return typeErr(t.Kind, value.Kind())
+	} else if t.T == FixedBytesTy && t.Size != value.Len() {
+		return typeErr(t.Type, value.Type())
+	} else {
+		return nil
+	}
+
+}
+
+// typeErr returns a formatted type casting error.
+func typeErr(expected, got interface{}) error {
+	return fmt.Errorf("abi: cannot use %v as type %v as argument", got, expected)
+}
diff --git a/accounts/abi/event.go b/accounts/abi/event.go
new file mode 100644
index 0000000..7a41baa
--- /dev/null
+++ b/accounts/abi/event.go
@@ -0,0 +1,77 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/crypto"
+)
+
+// Event is an event potentially triggered by the EVM's LOG mechanism. The Event
+// holds type information (inputs) about the yielded output. Anonymous events
+// don't get the signature canonical representation as the first LOG topic.
+type Event struct {
+	// Name is the event name used for internal representation. It's derived from
+	// the raw name and a suffix will be added in the case of a event overload.
+	//
+	// e.g.
+	// There are two events have same name:
+	// * foo(int,int)
+	// * foo(uint,uint)
+	// The event name of the first one wll be resolved as foo while the second one
+	// will be resolved as foo0.
+	Name string
+	// RawName is the raw event name parsed from ABI.
+	RawName   string
+	Anonymous bool
+	Inputs    Arguments
+}
+
+func (e Event) String() string {
+	inputs := make([]string, len(e.Inputs))
+	for i, input := range e.Inputs {
+		inputs[i] = fmt.Sprintf("%v %v", input.Type, input.Name)
+		if input.Indexed {
+			inputs[i] = fmt.Sprintf("%v indexed %v", input.Type, input.Name)
+		}
+	}
+	return fmt.Sprintf("event %v(%v)", e.RawName, strings.Join(inputs, ", "))
+}
+
+// Sig returns the event string signature according to the ABI spec.
+//
+// Example
+//
+//     event foo(uint32 a, int b) = "foo(uint32,int256)"
+//
+// Please note that "int" is substitute for its canonical representation "int256"
+func (e Event) Sig() string {
+	types := make([]string, len(e.Inputs))
+	for i, input := range e.Inputs {
+		types[i] = input.Type.String()
+	}
+	return fmt.Sprintf("%v(%v)", e.RawName, strings.Join(types, ","))
+}
+
+// ID returns the canonical representation of the event's signature used by the
+// abi definition to identify event names and types.
+func (e Event) ID() common.Hash {
+	return common.BytesToHash(crypto.Keccak256([]byte(e.Sig())))
+}
diff --git a/accounts/abi/method.go b/accounts/abi/method.go
new file mode 100644
index 0000000..9cceaba
--- /dev/null
+++ b/accounts/abi/method.go
@@ -0,0 +1,90 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/ava-labs/go-ethereum/crypto"
+)
+
+// Method represents a callable given a `Name` and whether the method is a constant.
+// If the method is `Const` no transaction needs to be created for this
+// particular Method call. It can easily be simulated using a local VM.
+// For example a `Balance()` method only needs to retrieve something
+// from the storage and therefore requires no Tx to be send to the
+// network. A method such as `Transact` does require a Tx and thus will
+// be flagged `false`.
+// Input specifies the required input parameters for this gives method.
+type Method struct {
+	// Name is the method name used for internal representation. It's derived from
+	// the raw name and a suffix will be added in the case of a function overload.
+	//
+	// e.g.
+	// There are two functions have same name:
+	// * foo(int,int)
+	// * foo(uint,uint)
+	// The method name of the first one will be resolved as foo while the second one
+	// will be resolved as foo0.
+	Name string
+	// RawName is the raw method name parsed from ABI.
+	RawName string
+	Const   bool
+	Inputs  Arguments
+	Outputs Arguments
+}
+
+// Sig returns the methods string signature according to the ABI spec.
+//
+// Example
+//
+//     function foo(uint32 a, int b) = "foo(uint32,int256)"
+//
+// Please note that "int" is substitute for its canonical representation "int256"
+func (method Method) Sig() string {
+	types := make([]string, len(method.Inputs))
+	for i, input := range method.Inputs {
+		types[i] = input.Type.String()
+	}
+	return fmt.Sprintf("%v(%v)", method.RawName, strings.Join(types, ","))
+}
+
+func (method Method) String() string {
+	inputs := make([]string, len(method.Inputs))
+	for i, input := range method.Inputs {
+		inputs[i] = fmt.Sprintf("%v %v", input.Type, input.Name)
+	}
+	outputs := make([]string, len(method.Outputs))
+	for i, output := range method.Outputs {
+		outputs[i] = output.Type.String()
+		if len(output.Name) > 0 {
+			outputs[i] += fmt.Sprintf(" %v", output.Name)
+		}
+	}
+	constant := ""
+	if method.Const {
+		constant = "constant "
+	}
+	return fmt.Sprintf("function %v(%v) %sreturns(%v)", method.RawName, strings.Join(inputs, ", "), constant, strings.Join(outputs, ", "))
+}
+
+// ID returns the canonical representation of the method's signature used by the
+// abi definition to identify method names and types.
+func (method Method) ID() []byte {
+	return crypto.Keccak256([]byte(method.Sig()))[:4]
+}
diff --git a/accounts/abi/numbers.go b/accounts/abi/numbers.go
new file mode 100644
index 0000000..c2e844c
--- /dev/null
+++ b/accounts/abi/numbers.go
@@ -0,0 +1,44 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"math/big"
+	"reflect"
+
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/common/math"
+)
+
+var (
+	bigT      = reflect.TypeOf(&big.Int{})
+	derefbigT = reflect.TypeOf(big.Int{})
+	uint8T    = reflect.TypeOf(uint8(0))
+	uint16T   = reflect.TypeOf(uint16(0))
+	uint32T   = reflect.TypeOf(uint32(0))
+	uint64T   = reflect.TypeOf(uint64(0))
+	int8T     = reflect.TypeOf(int8(0))
+	int16T    = reflect.TypeOf(int16(0))
+	int32T    = reflect.TypeOf(int32(0))
+	int64T    = reflect.TypeOf(int64(0))
+	addressT  = reflect.TypeOf(common.Address{})
+)
+
+// U256 converts a big Int into a 256bit EVM number.
+func U256(n *big.Int) []byte {
+	return math.PaddedBigBytes(math.U256(n), 32)
+}
diff --git a/accounts/abi/pack.go b/accounts/abi/pack.go
new file mode 100644
index 0000000..d88dde8
--- /dev/null
+++ b/accounts/abi/pack.go
@@ -0,0 +1,81 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"math/big"
+	"reflect"
+
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/common/math"
+)
+
+// packBytesSlice packs the given bytes as [L, V] as the canonical representation
+// bytes slice
+func packBytesSlice(bytes []byte, l int) []byte {
+	len := packNum(reflect.ValueOf(l))
+	return append(len, common.RightPadBytes(bytes, (l+31)/32*32)...)
+}
+
+// packElement packs the given reflect value according to the abi specification in
+// t.
+func packElement(t Type, reflectValue reflect.Value) []byte {
+	switch t.T {
+	case IntTy, UintTy:
+		return packNum(reflectValue)
+	case StringTy:
+		return packBytesSlice([]byte(reflectValue.String()), reflectValue.Len())
+	case AddressTy:
+		if reflectValue.Kind() == reflect.Array {
+			reflectValue = mustArrayToByteSlice(reflectValue)
+		}
+
+		return common.LeftPadBytes(reflectValue.Bytes(), 32)
+	case BoolTy:
+		if reflectValue.Bool() {
+			return math.PaddedBigBytes(common.Big1, 32)
+		}
+		return math.PaddedBigBytes(common.Big0, 32)
+	case BytesTy:
+		if reflectValue.Kind() == reflect.Array {
+			reflectValue = mustArrayToByteSlice(reflectValue)
+		}
+		return packBytesSlice(reflectValue.Bytes(), reflectValue.Len())
+	case FixedBytesTy, FunctionTy:
+		if reflectValue.Kind() == reflect.Array {
+			reflectValue = mustArrayToByteSlice(reflectValue)
+		}
+		return common.RightPadBytes(reflectValue.Bytes(), 32)
+	default:
+		panic("abi: fatal error")
+	}
+}
+
+// packNum packs the given number (using the reflect value) and will cast it to appropriate number representation
+func packNum(value reflect.Value) []byte {
+	switch kind := value.Kind(); kind {
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		return U256(new(big.Int).SetUint64(value.Uint()))
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return U256(big.NewInt(value.Int()))
+	case reflect.Ptr:
+		return U256(value.Interface().(*big.Int))
+	default:
+		panic("abi: fatal error")
+	}
+
+}
diff --git a/accounts/abi/reflect.go b/accounts/abi/reflect.go
new file mode 100644
index 0000000..73ca8fa
--- /dev/null
+++ b/accounts/abi/reflect.go
@@ -0,0 +1,226 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+// indirect recursively dereferences the value until it either gets the value
+// or finds a big.Int
+func indirect(v reflect.Value) reflect.Value {
+	if v.Kind() == reflect.Ptr && v.Elem().Type() != derefbigT {
+		return indirect(v.Elem())
+	}
+	return v
+}
+
+// indirectInterfaceOrPtr recursively dereferences the value until value is not interface.
+func indirectInterfaceOrPtr(v reflect.Value) reflect.Value {
+	if (v.Kind() == reflect.Interface || v.Kind() == reflect.Ptr) && v.Elem().IsValid() {
+		return indirect(v.Elem())
+	}
+	return v
+}
+
+// reflectIntKind returns the reflect using the given size and
+// unsignedness.
+func reflectIntKindAndType(unsigned bool, size int) (reflect.Kind, reflect.Type) {
+	switch size {
+	case 8:
+		if unsigned {
+			return reflect.Uint8, uint8T
+		}
+		return reflect.Int8, int8T
+	case 16:
+		if unsigned {
+			return reflect.Uint16, uint16T
+		}
+		return reflect.Int16, int16T
+	case 32:
+		if unsigned {
+			return reflect.Uint32, uint32T
+		}
+		return reflect.Int32, int32T
+	case 64:
+		if unsigned {
+			return reflect.Uint64, uint64T
+		}
+		return reflect.Int64, int64T
+	}
+	return reflect.Ptr, bigT
+}
+
+// mustArrayToBytesSlice creates a new byte slice with the exact same size as value
+// and copies the bytes in value to the new slice.
+func mustArrayToByteSlice(value reflect.Value) reflect.Value {
+	slice := reflect.MakeSlice(reflect.TypeOf([]byte{}), value.Len(), value.Len())
+	reflect.Copy(slice, value)
+	return slice
+}
+
+// set attempts to assign src to dst by either setting, copying or otherwise.
+//
+// set is a bit more lenient when it comes to assignment and doesn't force an as
+// strict ruleset as bare `reflect` does.
+func set(dst, src reflect.Value) error {
+	dstType, srcType := dst.Type(), src.Type()
+	switch {
+	case dstType.Kind() == reflect.Interface && dst.Elem().IsValid():
+		return set(dst.Elem(), src)
+	case dstType.Kind() == reflect.Ptr && dstType.Elem() != derefbigT:
+		return set(dst.Elem(), src)
+	case srcType.AssignableTo(dstType) && dst.CanSet():
+		dst.Set(src)
+	case dstType.Kind() == reflect.Slice && srcType.Kind() == reflect.Slice:
+		return setSlice(dst, src)
+	default:
+		return fmt.Errorf("abi: cannot unmarshal %v in to %v", src.Type(), dst.Type())
+	}
+	return nil
+}
+
+// setSlice attempts to assign src to dst when slices are not assignable by default
+// e.g. src: [][]byte -> dst: [][15]byte
+func setSlice(dst, src reflect.Value) error {
+	slice := reflect.MakeSlice(dst.Type(), src.Len(), src.Len())
+	for i := 0; i < src.Len(); i++ {
+		v := src.Index(i)
+		reflect.Copy(slice.Index(i), v)
+	}
+
+	dst.Set(slice)
+	return nil
+}
+
+// requireAssignable assures that `dest` is a pointer and it's not an interface.
+func requireAssignable(dst, src reflect.Value) error {
+	if dst.Kind() != reflect.Ptr && dst.Kind() != reflect.Interface {
+		return fmt.Errorf("abi: cannot unmarshal %v into %v", src.Type(), dst.Type())
+	}
+	return nil
+}
+
+// requireUnpackKind verifies preconditions for unpacking `args` into `kind`
+func requireUnpackKind(v reflect.Value, t reflect.Type, k reflect.Kind,
+	args Arguments) error {
+
+	switch k {
+	case reflect.Struct:
+	case reflect.Slice, reflect.Array:
+		if minLen := args.LengthNonIndexed(); v.Len() < minLen {
+			return fmt.Errorf("abi: insufficient number of elements in the list/array for unpack, want %d, got %d",
+				minLen, v.Len())
+		}
+	default:
+		return fmt.Errorf("abi: cannot unmarshal tuple into %v", t)
+	}
+	return nil
+}
+
+// mapArgNamesToStructFields maps a slice of argument names to struct fields.
+// first round: for each Exportable field that contains a `abi:""` tag
+//   and this field name exists in the given argument name list, pair them together.
+// second round: for each argument name that has not been already linked,
+//   find what variable is expected to be mapped into, if it exists and has not been
+//   used, pair them.
+// Note this function assumes the given value is a struct value.
+func mapArgNamesToStructFields(argNames []string, value reflect.Value) (map[string]string, error) {
+	typ := value.Type()
+
+	abi2struct := make(map[string]string)
+	struct2abi := make(map[string]string)
+
+	// first round ~~~
+	for i := 0; i < typ.NumField(); i++ {
+		structFieldName := typ.Field(i).Name
+
+		// skip private struct fields.
+		if structFieldName[:1] != strings.ToUpper(structFieldName[:1]) {
+			continue
+		}
+		// skip fields that have no abi:"" tag.
+		var ok bool
+		var tagName string
+		if tagName, ok = typ.Field(i).Tag.Lookup("abi"); !ok {
+			continue
+		}
+		// check if tag is empty.
+		if tagName == "" {
+			return nil, fmt.Errorf("struct: abi tag in '%s' is empty", structFieldName)
+		}
+		// check which argument field matches with the abi tag.
+		found := false
+		for _, arg := range argNames {
+			if arg == tagName {
+				if abi2struct[arg] != "" {
+					return nil, fmt.Errorf("struct: abi tag in '%s' already mapped", structFieldName)
+				}
+				// pair them
+				abi2struct[arg] = structFieldName
+				struct2abi[structFieldName] = arg
+				found = true
+			}
+		}
+		// check if this tag has been mapped.
+		if !found {
+			return nil, fmt.Errorf("struct: abi tag '%s' defined but not found in abi", tagName)
+		}
+	}
+
+	// second round ~~~
+	for _, argName := range argNames {
+
+		structFieldName := ToCamelCase(argName)
+
+		if structFieldName == "" {
+			return nil, fmt.Errorf("abi: purely underscored output cannot unpack to struct")
+		}
+
+		// this abi has already been paired, skip it... unless there exists another, yet unassigned
+		// struct field with the same field name. If so, raise an error:
+		//    abi: [ { "name": "value" } ]
+		//    struct { Value  *big.Int , Value1 *big.Int `abi:"value"`}
+		if abi2struct[argName] != "" {
+			if abi2struct[argName] != structFieldName &&
+				struct2abi[structFieldName] == "" &&
+				value.FieldByName(structFieldName).IsValid() {
+				return nil, fmt.Errorf("abi: multiple variables maps to the same abi field '%s'", argName)
+			}
+			continue
+		}
+
+		// return an error if this struct field has already been paired.
+		if struct2abi[structFieldName] != "" {
+			return nil, fmt.Errorf("abi: multiple outputs mapping to the same struct field '%s'", structFieldName)
+		}
+
+		if value.FieldByName(structFieldName).IsValid() {
+			// pair them
+			abi2struct[argName] = structFieldName
+			struct2abi[structFieldName] = argName
+		} else {
+			// not paired, but annotate as used, to detect cases like
+			//   abi : [ { "name": "value" }, { "name": "_value" } ]
+			//   struct { Value *big.Int }
+			struct2abi[structFieldName] = argName
+		}
+	}
+	return abi2struct, nil
+}
diff --git a/accounts/abi/type.go b/accounts/abi/type.go
new file mode 100644
index 0000000..597d314
--- /dev/null
+++ b/accounts/abi/type.go
@@ -0,0 +1,348 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// Type enumerator
+const (
+	IntTy byte = iota
+	UintTy
+	BoolTy
+	StringTy
+	SliceTy
+	ArrayTy
+	TupleTy
+	AddressTy
+	FixedBytesTy
+	BytesTy
+	HashTy
+	FixedPointTy
+	FunctionTy
+)
+
+// Type is the reflection of the supported argument type
+type Type struct {
+	Elem *Type
+	Kind reflect.Kind
+	Type reflect.Type
+	Size int
+	T    byte // Our own type checking
+
+	stringKind string // holds the unparsed string for deriving signatures
+
+	// Tuple relative fields
+	TupleElems    []*Type  // Type information of all tuple fields
+	TupleRawNames []string // Raw field name of all tuple fields
+}
+
+var (
+	// typeRegex parses the abi sub types
+	typeRegex = regexp.MustCompile("([a-zA-Z]+)(([0-9]+)(x([0-9]+))?)?")
+)
+
+// NewType creates a new reflection type of abi type given in t.
+func NewType(t string, components []ArgumentMarshaling) (typ Type, err error) {
+	// check that array brackets are equal if they exist
+	if strings.Count(t, "[") != strings.Count(t, "]") {
+		return Type{}, fmt.Errorf("invalid arg type in abi")
+	}
+	typ.stringKind = t
+
+	// if there are brackets, get ready to go into slice/array mode and
+	// recursively create the type
+	if strings.Count(t, "[") != 0 {
+		i := strings.LastIndex(t, "[")
+		// recursively embed the type
+		embeddedType, err := NewType(t[:i], components)
+		if err != nil {
+			return Type{}, err
+		}
+		// grab the last cell and create a type from there
+		sliced := t[i:]
+		// grab the slice size with regexp
+		re := regexp.MustCompile("[0-9]+")
+		intz := re.FindAllString(sliced, -1)
+
+		if len(intz) == 0 {
+			// is a slice
+			typ.T = SliceTy
+			typ.Kind = reflect.Slice
+			typ.Elem = &embeddedType
+			typ.Type = reflect.SliceOf(embeddedType.Type)
+			typ.stringKind = embeddedType.stringKind + sliced
+		} else if len(intz) == 1 {
+			// is a array
+			typ.T = ArrayTy
+			typ.Kind = reflect.Array
+			typ.Elem = &embeddedType
+			typ.Size, err = strconv.Atoi(intz[0])
+			if err != nil {
+				return Type{}, fmt.Errorf("abi: error parsing variable size: %v", err)
+			}
+			typ.Type = reflect.ArrayOf(typ.Size, embeddedType.Type)
+			typ.stringKind = embeddedType.stringKind + sliced
+		} else {
+			return Type{}, fmt.Errorf("invalid formatting of array type")
+		}
+		return typ, err
+	}
+	// parse the type and size of the abi-type.
+	matches := typeRegex.FindAllStringSubmatch(t, -1)
+	if len(matches) == 0 {
+		return Type{}, fmt.Errorf("invalid type '%v'", t)
+	}
+	parsedType := matches[0]
+
+	// varSize is the size of the variable
+	var varSize int
+	if len(parsedType[3]) > 0 {
+		var err error
+		varSize, err = strconv.Atoi(parsedType[2])
+		if err != nil {
+			return Type{}, fmt.Errorf("abi: error parsing variable size: %v", err)
+		}
+	} else {
+		if parsedType[0] == "uint" || parsedType[0] == "int" {
+			// this should fail because it means that there's something wrong with
+			// the abi type (the compiler should always format it to the size...always)
+			return Type{}, fmt.Errorf("unsupported arg type: %s", t)
+		}
+	}
+	// varType is the parsed abi type
+	switch varType := parsedType[1]; varType {
+	case "int":
+		typ.Kind, typ.Type = reflectIntKindAndType(false, varSize)
+		typ.Size = varSize
+		typ.T = IntTy
+	case "uint":
+		typ.Kind, typ.Type = reflectIntKindAndType(true, varSize)
+		typ.Size = varSize
+		typ.T = UintTy
+	case "bool":
+		typ.Kind = reflect.Bool
+		typ.T = BoolTy
+		typ.Type = reflect.TypeOf(bool(false))
+	case "address":
+		typ.Kind = reflect.Array
+		typ.Type = addressT
+		typ.Size = 20
+		typ.T = AddressTy
+	case "string":
+		typ.Kind = reflect.String
+		typ.Type = reflect.TypeOf("")
+		typ.T = StringTy
+	case "bytes":
+		if varSize == 0 {
+			typ.T = BytesTy
+			typ.Kind = reflect.Slice
+			typ.Type = reflect.SliceOf(reflect.TypeOf(byte(0)))
+		} else {
+			typ.T = FixedBytesTy
+			typ.Kind = reflect.Array
+			typ.Size = varSize
+			typ.Type = reflect.ArrayOf(varSize, reflect.TypeOf(byte(0)))
+		}
+	case "tuple":
+		var (
+			fields     []reflect.StructField
+			elems      []*Type
+			names      []string
+			expression string // canonical parameter expression
+		)
+		expression += "("
+		for idx, c := range components {
+			cType, err := NewType(c.Type, c.Components)
+			if err != nil {
+				return Type{}, err
+			}
+			if ToCamelCase(c.Name) == "" {
+				return Type{}, errors.New("abi: purely anonymous or underscored field is not supported")
+			}
+			fields = append(fields, reflect.StructField{
+				Name: ToCamelCase(c.Name), // reflect.StructOf will panic for any exported field.
+				Type: cType.Type,
+				Tag:  reflect.StructTag("json:\"" + c.Name + "\""),
+			})
+			elems = append(elems, &cType)
+			names = append(names, c.Name)
+			expression += cType.stringKind
+			if idx != len(components)-1 {
+				expression += ","
+			}
+		}
+		expression += ")"
+		typ.Kind = reflect.Struct
+		typ.Type = reflect.StructOf(fields)
+		typ.TupleElems = elems
+		typ.TupleRawNames = names
+		typ.T = TupleTy
+		typ.stringKind = expression
+	case "function":
+		typ.Kind = reflect.Array
+		typ.T = FunctionTy
+		typ.Size = 24
+		typ.Type = reflect.ArrayOf(24, reflect.TypeOf(byte(0)))
+	default:
+		return Type{}, fmt.Errorf("unsupported arg type: %s", t)
+	}
+
+	return
+}
+
+// String implements Stringer
+func (t Type) String() (out string) {
+	return t.stringKind
+}
+
+func (t Type) pack(v reflect.Value) ([]byte, error) {
+	// dereference pointer first if it's a pointer
+	v = indirect(v)
+	if err := typeCheck(t, v); err != nil {
+		return nil, err
+	}
+
+	switch t.T {
+	case SliceTy, ArrayTy:
+		var ret []byte
+
+		if t.requiresLengthPrefix() {
+			// append length
+			ret = append(ret, packNum(reflect.ValueOf(v.Len()))...)
+		}
+
+		// calculate offset if any
+		offset := 0
+		offsetReq := isDynamicType(*t.Elem)
+		if offsetReq {
+			offset = getTypeSize(*t.Elem) * v.Len()
+		}
+		var tail []byte
+		for i := 0; i < v.Len(); i++ {
+			val, err := t.Elem.pack(v.Index(i))
+			if err != nil {
+				return nil, err
+			}
+			if !offsetReq {
+				ret = append(ret, val...)
+				continue
+			}
+			ret = append(ret, packNum(reflect.ValueOf(offset))...)
+			offset += len(val)
+			tail = append(tail, val...)
+		}
+		return append(ret, tail...), nil
+	case TupleTy:
+		// (T1,...,Tk) for k >= 0 and any types T1, …, Tk
+		// enc(X) = head(X(1)) ... head(X(k)) tail(X(1)) ... tail(X(k))
+		// where X = (X(1), ..., X(k)) and head and tail are defined for Ti being a static
+		// type as
+		//     head(X(i)) = enc(X(i)) and tail(X(i)) = "" (the empty string)
+		// and as
+		//     head(X(i)) = enc(len(head(X(1)) ... head(X(k)) tail(X(1)) ... tail(X(i-1))))
+		//     tail(X(i)) = enc(X(i))
+		// otherwise, i.e. if Ti is a dynamic type.
+		fieldmap, err := mapArgNamesToStructFields(t.TupleRawNames, v)
+		if err != nil {
+			return nil, err
+		}
+		// Calculate prefix occupied size.
+		offset := 0
+		for _, elem := range t.TupleElems {
+			offset += getTypeSize(*elem)
+		}
+		var ret, tail []byte
+		for i, elem := range t.TupleElems {
+			field := v.FieldByName(fieldmap[t.TupleRawNames[i]])
+			if !field.IsValid() {
+				return nil, fmt.Errorf("field %s for tuple not found in the given struct", t.TupleRawNames[i])
+			}
+			val, err := elem.pack(field)
+			if err != nil {
+				return nil, err
+			}
+			if isDynamicType(*elem) {
+				ret = append(ret, packNum(reflect.ValueOf(offset))...)
+				tail = append(tail, val...)
+				offset += len(val)
+			} else {
+				ret = append(ret, val...)
+			}
+		}
+		return append(ret, tail...), nil
+
+	default:
+		return packElement(t, v), nil
+	}
+}
+
+// requireLengthPrefix returns whether the type requires any sort of length
+// prefixing.
+func (t Type) requiresLengthPrefix() bool {
+	return t.T == StringTy || t.T == BytesTy || t.T == SliceTy
+}
+
+// isDynamicType returns true if the type is dynamic.
+// The following types are called “dynamic”:
+// * bytes
+// * string
+// * T[] for any T
+// * T[k] for any dynamic T and any k >= 0
+// * (T1,...,Tk) if Ti is dynamic for some 1 <= i <= k
+func isDynamicType(t Type) bool {
+	if t.T == TupleTy {
+		for _, elem := range t.TupleElems {
+			if isDynamicType(*elem) {
+				return true
+			}
+		}
+		return false
+	}
+	return t.T == StringTy || t.T == BytesTy || t.T == SliceTy || (t.T == ArrayTy && isDynamicType(*t.Elem))
+}
+
+// getTypeSize returns the size that this type needs to occupy.
+// We distinguish static and dynamic types. Static types are encoded in-place
+// and dynamic types are encoded at a separately allocated location after the
+// current block.
+// So for a static variable, the size returned represents the size that the
+// variable actually occupies.
+// For a dynamic variable, the returned size is fixed 32 bytes, which is used
+// to store the location reference for actual value storage.
+func getTypeSize(t Type) int {
+	if t.T == ArrayTy && !isDynamicType(*t.Elem) {
+		// Recursively calculate type size if it is a nested array
+		if t.Elem.T == ArrayTy {
+			return t.Size * getTypeSize(*t.Elem)
+		}
+		return t.Size * 32
+	} else if t.T == TupleTy && !isDynamicType(t) {
+		total := 0
+		for _, elem := range t.TupleElems {
+			total += getTypeSize(*elem)
+		}
+		return total
+	}
+	return 32
+}
diff --git a/accounts/abi/unpack.go b/accounts/abi/unpack.go
new file mode 100644
index 0000000..d3cd310
--- /dev/null
+++ b/accounts/abi/unpack.go
@@ -0,0 +1,295 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"encoding/binary"
+	"fmt"
+	"math/big"
+	"reflect"
+
+	"github.com/ava-labs/go-ethereum/common"
+)
+
+var (
+	maxUint256 = big.NewInt(0).Add(
+		big.NewInt(0).Exp(big.NewInt(2), big.NewInt(256), nil),
+		big.NewInt(-1))
+	maxInt256 = big.NewInt(0).Add(
+		big.NewInt(0).Exp(big.NewInt(2), big.NewInt(255), nil),
+		big.NewInt(-1))
+)
+
+// reads the integer based on its kind
+func readInteger(typ byte, kind reflect.Kind, b []byte) interface{} {
+	switch kind {
+	case reflect.Uint8:
+		return b[len(b)-1]
+	case reflect.Uint16:
+		return binary.BigEndian.Uint16(b[len(b)-2:])
+	case reflect.Uint32:
+		return binary.BigEndian.Uint32(b[len(b)-4:])
+	case reflect.Uint64:
+		return binary.BigEndian.Uint64(b[len(b)-8:])
+	case reflect.Int8:
+		return int8(b[len(b)-1])
+	case reflect.Int16:
+		return int16(binary.BigEndian.Uint16(b[len(b)-2:]))
+	case reflect.Int32:
+		return int32(binary.BigEndian.Uint32(b[len(b)-4:]))
+	case reflect.Int64:
+		return int64(binary.BigEndian.Uint64(b[len(b)-8:]))
+	default:
+		// the only case lefts for integer is int256/uint256.
+		// big.SetBytes can't tell if a number is negative, positive on itself.
+		// On EVM, if the returned number > max int256, it is negative.
+		ret := new(big.Int).SetBytes(b)
+		if typ == UintTy {
+			return ret
+		}
+
+		if ret.Cmp(maxInt256) > 0 {
+			ret.Add(maxUint256, big.NewInt(0).Neg(ret))
+			ret.Add(ret, big.NewInt(1))
+			ret.Neg(ret)
+		}
+		return ret
+	}
+}
+
+// reads a bool
+func readBool(word []byte) (bool, error) {
+	for _, b := range word[:31] {
+		if b != 0 {
+			return false, errBadBool
+		}
+	}
+	switch word[31] {
+	case 0:
+		return false, nil
+	case 1:
+		return true, nil
+	default:
+		return false, errBadBool
+	}
+}
+
+// A function type is simply the address with the function selection signature at the end.
+// This enforces that standard by always presenting it as a 24-array (address + sig = 24 bytes)
+func readFunctionType(t Type, word []byte) (funcTy [24]byte, err error) {
+	if t.T != FunctionTy {
+		return [24]byte{}, fmt.Errorf("abi: invalid type in call to make function type byte array")
+	}
+	if garbage := binary.BigEndian.Uint64(word[24:32]); garbage != 0 {
+		err = fmt.Errorf("abi: got improperly encoded function type, got %v", word)
+	} else {
+		copy(funcTy[:], word[0:24])
+	}
+	return
+}
+
+// through reflection, creates a fixed array to be read from
+func readFixedBytes(t Type, word []byte) (interface{}, error) {
+	if t.T != FixedBytesTy {
+		return nil, fmt.Errorf("abi: invalid type in call to make fixed byte array")
+	}
+	// convert
+	array := reflect.New(t.Type).Elem()
+
+	reflect.Copy(array, reflect.ValueOf(word[0:t.Size]))
+	return array.Interface(), nil
+
+}
+
+// iteratively unpack elements
+func forEachUnpack(t Type, output []byte, start, size int) (interface{}, error) {
+	if size < 0 {
+		return nil, fmt.Errorf("cannot marshal input to array, size is negative (%d)", size)
+	}
+	if start+32*size > len(output) {
+		return nil, fmt.Errorf("abi: cannot marshal in to go array: offset %d would go over slice boundary (len=%d)", len(output), start+32*size)
+	}
+
+	// this value will become our slice or our array, depending on the type
+	var refSlice reflect.Value
+
+	if t.T == SliceTy {
+		// declare our slice
+		refSlice = reflect.MakeSlice(t.Type, size, size)
+	} else if t.T == ArrayTy {
+		// declare our array
+		refSlice = reflect.New(t.Type).Elem()
+	} else {
+		return nil, fmt.Errorf("abi: invalid type in array/slice unpacking stage")
+	}
+
+	// Arrays have packed elements, resulting in longer unpack steps.
+	// Slices have just 32 bytes per element (pointing to the contents).
+	elemSize := getTypeSize(*t.Elem)
+
+	for i, j := start, 0; j < size; i, j = i+elemSize, j+1 {
+		inter, err := toGoType(i, *t.Elem, output)
+		if err != nil {
+			return nil, err
+		}
+
+		// append the item to our reflect slice
+		refSlice.Index(j).Set(reflect.ValueOf(inter))
+	}
+
+	// return the interface
+	return refSlice.Interface(), nil
+}
+
+func forTupleUnpack(t Type, output []byte) (interface{}, error) {
+	retval := reflect.New(t.Type).Elem()
+	virtualArgs := 0
+	for index, elem := range t.TupleElems {
+		marshalledValue, err := toGoType((index+virtualArgs)*32, *elem, output)
+		if elem.T == ArrayTy && !isDynamicType(*elem) {
+			// If we have a static array, like [3]uint256, these are coded as
+			// just like uint256,uint256,uint256.
+			// This means that we need to add two 'virtual' arguments when
+			// we count the index from now on.
+			//
+			// Array values nested multiple levels deep are also encoded inline:
+			// [2][3]uint256: uint256,uint256,uint256,uint256,uint256,uint256
+			//
+			// Calculate the full array size to get the correct offset for the next argument.
+			// Decrement it by 1, as the normal index increment is still applied.
+			virtualArgs += getTypeSize(*elem)/32 - 1
+		} else if elem.T == TupleTy && !isDynamicType(*elem) {
+			// If we have a static tuple, like (uint256, bool, uint256), these are
+			// coded as just like uint256,bool,uint256
+			virtualArgs += getTypeSize(*elem)/32 - 1
+		}
+		if err != nil {
+			return nil, err
+		}
+		retval.Field(index).Set(reflect.ValueOf(marshalledValue))
+	}
+	return retval.Interface(), nil
+}
+
+// toGoType parses the output bytes and recursively assigns the value of these bytes
+// into a go type with accordance with the ABI spec.
+func toGoType(index int, t Type, output []byte) (interface{}, error) {
+	if index+32 > len(output) {
+		return nil, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %d require %d", len(output), index+32)
+	}
+
+	var (
+		returnOutput  []byte
+		begin, length int
+		err           error
+	)
+
+	// if we require a length prefix, find the beginning word and size returned.
+	if t.requiresLengthPrefix() {
+		begin, length, err = lengthPrefixPointsTo(index, output)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		returnOutput = output[index : index+32]
+	}
+
+	switch t.T {
+	case TupleTy:
+		if isDynamicType(t) {
+			begin, err := tuplePointsTo(index, output)
+			if err != nil {
+				return nil, err
+			}
+			return forTupleUnpack(t, output[begin:])
+		} else {
+			return forTupleUnpack(t, output[index:])
+		}
+	case SliceTy:
+		return forEachUnpack(t, output[begin:], 0, length)
+	case ArrayTy:
+		if isDynamicType(*t.Elem) {
+			offset := int64(binary.BigEndian.Uint64(returnOutput[len(returnOutput)-8:]))
+			return forEachUnpack(t, output[offset:], 0, t.Size)
+		}
+		return forEachUnpack(t, output[index:], 0, t.Size)
+	case StringTy: // variable arrays are written at the end of the return bytes
+		return string(output[begin : begin+length]), nil
+	case IntTy, UintTy:
+		return readInteger(t.T, t.Kind, returnOutput), nil
+	case BoolTy:
+		return readBool(returnOutput)
+	case AddressTy:
+		return common.BytesToAddress(returnOutput), nil
+	case HashTy:
+		return common.BytesToHash(returnOutput), nil
+	case BytesTy:
+		return output[begin : begin+length], nil
+	case FixedBytesTy:
+		return readFixedBytes(t, returnOutput)
+	case FunctionTy:
+		return readFunctionType(t, returnOutput)
+	default:
+		return nil, fmt.Errorf("abi: unknown type %v", t.T)
+	}
+}
+
+// interprets a 32 byte slice as an offset and then determines which indice to look to decode the type.
+func lengthPrefixPointsTo(index int, output []byte) (start int, length int, err error) {
+	bigOffsetEnd := big.NewInt(0).SetBytes(output[index : index+32])
+	bigOffsetEnd.Add(bigOffsetEnd, common.Big32)
+	outputLength := big.NewInt(int64(len(output)))
+
+	if bigOffsetEnd.Cmp(outputLength) > 0 {
+		return 0, 0, fmt.Errorf("abi: cannot marshal in to go slice: offset %v would go over slice boundary (len=%v)", bigOffsetEnd, outputLength)
+	}
+
+	if bigOffsetEnd.BitLen() > 63 {
+		return 0, 0, fmt.Errorf("abi offset larger than int64: %v", bigOffsetEnd)
+	}
+
+	offsetEnd := int(bigOffsetEnd.Uint64())
+	lengthBig := big.NewInt(0).SetBytes(output[offsetEnd-32 : offsetEnd])
+
+	totalSize := big.NewInt(0)
+	totalSize.Add(totalSize, bigOffsetEnd)
+	totalSize.Add(totalSize, lengthBig)
+	if totalSize.BitLen() > 63 {
+		return 0, 0, fmt.Errorf("abi: length larger than int64: %v", totalSize)
+	}
+
+	if totalSize.Cmp(outputLength) > 0 {
+		return 0, 0, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %v require %v", outputLength, totalSize)
+	}
+	start = int(bigOffsetEnd.Uint64())
+	length = int(lengthBig.Uint64())
+	return
+}
+
+// tuplePointsTo resolves the location reference for dynamic tuple.
+func tuplePointsTo(index int, output []byte) (start int, err error) {
+	offset := big.NewInt(0).SetBytes(output[index : index+32])
+	outputLen := big.NewInt(int64(len(output)))
+
+	if offset.Cmp(big.NewInt(int64(len(output)))) > 0 {
+		return 0, fmt.Errorf("abi: cannot marshal in to go slice: offset %v would go over slice boundary (len=%v)", offset, outputLen)
+	}
+	if offset.BitLen() > 63 {
+		return 0, fmt.Errorf("abi offset larger than int64: %v", offset)
+	}
+	return int(offset.Uint64()), nil
+}
diff --git a/accounts/accounts.go b/accounts/accounts.go
new file mode 100644
index 0000000..bca3223
--- /dev/null
+++ b/accounts/accounts.go
@@ -0,0 +1,222 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package accounts implements high level Ethereum account management.
+package accounts
+
+import (
+	"fmt"
+	"math/big"
+
+	"github.com/ava-labs/coreth/core/types"
+	ethereum "github.com/ava-labs/go-ethereum"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/event"
+	"golang.org/x/crypto/sha3"
+)
+
+// Account represents an Ethereum account located at a specific location defined
+// by the optional URL field.
+type Account struct {
+	Address common.Address `json:"address"` // Ethereum account address derived from the key
+	URL     URL            `json:"url"`     // Optional resource locator within a backend
+}
+
+const (
+	MimetypeDataWithValidator = "data/validator"
+	MimetypeTypedData         = "data/typed"
+	MimetypeClique            = "application/x-clique-header"
+	MimetypeTextPlain         = "text/plain"
+)
+
+// Wallet represents a software or hardware wallet that might contain one or more
+// accounts (derived from the same seed).
+type Wallet interface {
+	// URL retrieves the canonical path under which this wallet is reachable. It is
+	// user by upper layers to define a sorting order over all wallets from multiple
+	// backends.
+	URL() URL
+
+	// Status returns a textual status to aid the user in the current state of the
+	// wallet. It also returns an error indicating any failure the wallet might have
+	// encountered.
+	Status() (string, error)
+
+	// Open initializes access to a wallet instance. It is not meant to unlock or
+	// decrypt account keys, rather simply to establish a connection to hardware
+	// wallets and/or to access derivation seeds.
+	//
+	// The passphrase parameter may or may not be used by the implementation of a
+	// particular wallet instance. The reason there is no passwordless open method
+	// is to strive towards a uniform wallet handling, oblivious to the different
+	// backend providers.
+	//
+	// Please note, if you open a wallet, you must close it to release any allocated
+	// resources (especially important when working with hardware wallets).
+	Open(passphrase string) error
+
+	// Close releases any resources held by an open wallet instance.
+	Close() error
+
+	// Accounts retrieves the list of signing accounts the wallet is currently aware
+	// of. For hierarchical deterministic wallets, the list will not be exhaustive,
+	// rather only contain the accounts explicitly pinned during account derivation.
+	Accounts() []Account
+
+	// Contains returns whether an account is part of this particular wallet or not.
+	Contains(account Account) bool
+
+	// Derive attempts to explicitly derive a hierarchical deterministic account at
+	// the specified derivation path. If requested, the derived account will be added
+	// to the wallet's tracked account list.
+	Derive(path DerivationPath, pin bool) (Account, error)
+
+	// SelfDerive sets a base account derivation path from which the wallet attempts
+	// to discover non zero accounts and automatically add them to list of tracked
+	// accounts.
+	//
+	// Note, self derivaton will increment the last component of the specified path
+	// opposed to decending into a child path to allow discovering accounts starting
+	// from non zero components.
+	//
+	// Some hardware wallets switched derivation paths through their evolution, so
+	// this method supports providing multiple bases to discover old user accounts
+	// too. Only the last base will be used to derive the next empty account.
+	//
+	// You can disable automatic account discovery by calling SelfDerive with a nil
+	// chain state reader.
+	SelfDerive(bases []DerivationPath, chain ethereum.ChainStateReader)
+
+	// SignData requests the wallet to sign the hash of the given data
+	// It looks up the account specified either solely via its address contained within,
+	// or optionally with the aid of any location metadata from the embedded URL field.
+	//
+	// If the wallet requires additional authentication to sign the request (e.g.
+	// a password to decrypt the account, or a PIN code o verify the transaction),
+	// an AuthNeededError instance will be returned, containing infos for the user
+	// about which fields or actions are needed. The user may retry by providing
+	// the needed details via SignDataWithPassphrase, or by other means (e.g. unlock
+	// the account in a keystore).
+	SignData(account Account, mimeType string, data []byte) ([]byte, error)
+
+	// SignDataWithPassphrase is identical to SignData, but also takes a password
+	// NOTE: there's an chance that an erroneous call might mistake the two strings, and
+	// supply password in the mimetype field, or vice versa. Thus, an implementation
+	// should never echo the mimetype or return the mimetype in the error-response
+	SignDataWithPassphrase(account Account, passphrase, mimeType string, data []byte) ([]byte, error)
+
+	// SignText requests the wallet to sign the hash of a given piece of data, prefixed
+	// by the Ethereum prefix scheme
+	// It looks up the account specified either solely via its address contained within,
+	// or optionally with the aid of any location metadata from the embedded URL field.
+	//
+	// If the wallet requires additional authentication to sign the request (e.g.
+	// a password to decrypt the account, or a PIN code o verify the transaction),
+	// an AuthNeededError instance will be returned, containing infos for the user
+	// about which fields or actions are needed. The user may retry by providing
+	// the needed details via SignHashWithPassphrase, or by other means (e.g. unlock
+	// the account in a keystore).
+	SignText(account Account, text []byte) ([]byte, error)
+
+	// SignTextWithPassphrase is identical to Signtext, but also takes a password
+	SignTextWithPassphrase(account Account, passphrase string, hash []byte) ([]byte, error)
+
+	// SignTx requests the wallet to sign the given transaction.
+	//
+	// It looks up the account specified either solely via its address contained within,
+	// or optionally with the aid of any location metadata from the embedded URL field.
+	//
+	// If the wallet requires additional authentication to sign the request (e.g.
+	// a password to decrypt the account, or a PIN code to verify the transaction),
+	// an AuthNeededError instance will be returned, containing infos for the user
+	// about which fields or actions are needed. The user may retry by providing
+	// the needed details via SignTxWithPassphrase, or by other means (e.g. unlock
+	// the account in a keystore).
+	SignTx(account Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error)
+
+	// SignTxWithPassphrase is identical to SignTx, but also takes a password
+	SignTxWithPassphrase(account Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error)
+}
+
+// Backend is a "wallet provider" that may contain a batch of accounts they can
+// sign transactions with and upon request, do so.
+type Backend interface {
+	// Wallets retrieves the list of wallets the backend is currently aware of.
+	//
+	// The returned wallets are not opened by default. For software HD wallets this
+	// means that no base seeds are decrypted, and for hardware wallets that no actual
+	// connection is established.
+	//
+	// The resulting wallet list will be sorted alphabetically based on its internal
+	// URL assigned by the backend. Since wallets (especially hardware) may come and
+	// go, the same wallet might appear at a different positions in the list during
+	// subsequent retrievals.
+	Wallets() []Wallet
+
+	// Subscribe creates an async subscription to receive notifications when the
+	// backend detects the arrival or departure of a wallet.
+	Subscribe(sink chan<- WalletEvent) event.Subscription
+}
+
+// TextHash is a helper function that calculates a hash for the given message that can be
+// safely used to calculate a signature from.
+//
+// The hash is calulcated as
+//   keccak256("\x19Ethereum Signed Message:\n"${message length}${message}).
+//
+// This gives context to the signed message and prevents signing of transactions.
+func TextHash(data []byte) []byte {
+	hash, _ := TextAndHash(data)
+	return hash
+}
+
+// TextAndHash is a helper function that calculates a hash for the given message that can be
+// safely used to calculate a signature from.
+//
+// The hash is calulcated as
+//   keccak256("\x19Ethereum Signed Message:\n"${message length}${message}).
+//
+// This gives context to the signed message and prevents signing of transactions.
+func TextAndHash(data []byte) ([]byte, string) {
+	msg := fmt.Sprintf("\x19Ethereum Signed Message:\n%d%s", len(data), string(data))
+	hasher := sha3.NewLegacyKeccak256()
+	hasher.Write([]byte(msg))
+	return hasher.Sum(nil), msg
+}
+
+// WalletEventType represents the different event types that can be fired by
+// the wallet subscription subsystem.
+type WalletEventType int
+
+const (
+	// WalletArrived is fired when a new wallet is detected either via USB or via
+	// a filesystem event in the keystore.
+	WalletArrived WalletEventType = iota
+
+	// WalletOpened is fired when a wallet is successfully opened with the purpose
+	// of starting any background processes such as automatic key derivation.
+	WalletOpened
+
+	// WalletDropped
+	WalletDropped
+)
+
+// WalletEvent is an event fired by an account backend when a wallet arrival or
+// departure is detected.
+type WalletEvent struct {
+	Wallet Wallet          // Wallet instance arrived or departed
+	Kind   WalletEventType // Event type that happened in the system
+}
diff --git a/accounts/errors.go b/accounts/errors.go
new file mode 100644
index 0000000..2fed35f
--- /dev/null
+++ b/accounts/errors.go
@@ -0,0 +1,68 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+import (
+	"errors"
+	"fmt"
+)
+
+// ErrUnknownAccount is returned for any requested operation for which no backend
+// provides the specified account.
+var ErrUnknownAccount = errors.New("unknown account")
+
+// ErrUnknownWallet is returned for any requested operation for which no backend
+// provides the specified wallet.
+var ErrUnknownWallet = errors.New("unknown wallet")
+
+// ErrNotSupported is returned when an operation is requested from an account
+// backend that it does not support.
+var ErrNotSupported = errors.New("not supported")
+
+// ErrInvalidPassphrase is returned when a decryption operation receives a bad
+// passphrase.
+var ErrInvalidPassphrase = errors.New("invalid password")
+
+// ErrWalletAlreadyOpen is returned if a wallet is attempted to be opened the
+// second time.
+var ErrWalletAlreadyOpen = errors.New("wallet already open")
+
+// ErrWalletClosed is returned if a wallet is attempted to be opened the
+// secodn time.
+var ErrWalletClosed = errors.New("wallet closed")
+
+// AuthNeededError is returned by backends for signing requests where the user
+// is required to provide further authentication before signing can succeed.
+//
+// This usually means either that a password needs to be supplied, or perhaps a
+// one time PIN code displayed by some hardware device.
+type AuthNeededError struct {
+	Needed string // Extra authentication the user needs to provide
+}
+
+// NewAuthNeededError creates a new authentication error with the extra details
+// about the needed fields set.
+func NewAuthNeededError(needed string) error {
+	return &AuthNeededError{
+		Needed: needed,
+	}
+}
+
+// Error implements the standard error interface.
+func (err *AuthNeededError) Error() string {
+	return fmt.Sprintf("authentication needed: %s", err.Needed)
+}
diff --git a/accounts/external/backend.go b/accounts/external/backend.go
new file mode 100644
index 0000000..16e201d
--- /dev/null
+++ b/accounts/external/backend.go
@@ -0,0 +1,231 @@
+// Copyright 2019 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package external
+
+import (
+	"fmt"
+	"math/big"
+	"sync"
+
+	"github.com/ava-labs/coreth/accounts"
+	"github.com/ava-labs/coreth/core/types"
+	"github.com/ava-labs/coreth/internal/ethapi"
+	"github.com/ava-labs/coreth/rpc"
+	"github.com/ava-labs/go-ethereum"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/common/hexutil"
+	"github.com/ava-labs/go-ethereum/event"
+	"github.com/ava-labs/go-ethereum/log"
+	"github.com/ava-labs/go-ethereum/signer/core"
+)
+
+type ExternalBackend struct {
+	signers []accounts.Wallet
+}
+
+func (eb *ExternalBackend) Wallets() []accounts.Wallet {
+	return eb.signers
+}
+
+func NewExternalBackend(endpoint string) (*ExternalBackend, error) {
+	signer, err := NewExternalSigner(endpoint)
+	if err != nil {
+		return nil, err
+	}
+	return &ExternalBackend{
+		signers: []accounts.Wallet{signer},
+	}, nil
+}
+
+func (eb *ExternalBackend) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription {
+	return event.NewSubscription(func(quit <-chan struct{}) error {
+		<-quit
+		return nil
+	})
+}
+
+// ExternalSigner provides an API to interact with an external signer (clef)
+// It proxies request to the external signer while forwarding relevant
+// request headers
+type ExternalSigner struct {
+	client   *rpc.Client
+	endpoint string
+	status   string
+	cacheMu  sync.RWMutex
+	cache    []accounts.Account
+}
+
+func NewExternalSigner(endpoint string) (*ExternalSigner, error) {
+	client, err := rpc.Dial(endpoint)
+	if err != nil {
+		return nil, err
+	}
+	extsigner := &ExternalSigner{
+		client:   client,
+		endpoint: endpoint,
+	}
+	// Check if reachable
+	version, err := extsigner.pingVersion()
+	if err != nil {
+		return nil, err
+	}
+	extsigner.status = fmt.Sprintf("ok [version=%v]", version)
+	return extsigner, nil
+}
+
+func (api *ExternalSigner) URL() accounts.URL {
+	return accounts.URL{
+		Scheme: "extapi",
+		Path:   api.endpoint,
+	}
+}
+
+func (api *ExternalSigner) Status() (string, error) {
+	return api.status, nil
+}
+
+func (api *ExternalSigner) Open(passphrase string) error {
+	return fmt.Errorf("operation not supported on external signers")
+}
+
+func (api *ExternalSigner) Close() error {
+	return fmt.Errorf("operation not supported on external signers")
+}
+
+func (api *ExternalSigner) Accounts() []accounts.Account {
+	var accnts []accounts.Account
+	res, err := api.listAccounts()
+	if err != nil {
+		log.Error("account listing failed", "error", err)
+		return accnts
+	}
+	for _, addr := range res {
+		accnts = append(accnts, accounts.Account{
+			URL: accounts.URL{
+				Scheme: "extapi",
+				Path:   api.endpoint,
+			},
+			Address: addr,
+		})
+	}
+	api.cacheMu.Lock()
+	api.cache = accnts
+	api.cacheMu.Unlock()
+	return accnts
+}
+
+func (api *ExternalSigner) Contains(account accounts.Account) bool {
+	api.cacheMu.RLock()
+	defer api.cacheMu.RUnlock()
+	for _, a := range api.cache {
+		if a.Address == account.Address && (account.URL == (accounts.URL{}) || account.URL == api.URL()) {
+			return true
+		}
+	}
+	return false
+}
+
+func (api *ExternalSigner) Derive(path accounts.DerivationPath, pin bool) (accounts.Account, error) {
+	return accounts.Account{}, fmt.Errorf("operation not supported on external signers")
+}
+
+func (api *ExternalSigner) SelfDerive(bases []accounts.DerivationPath, chain ethereum.ChainStateReader) {
+	log.Error("operation SelfDerive not supported on external signers")
+}
+
+func (api *ExternalSigner) signHash(account accounts.Account, hash []byte) ([]byte, error) {
+	return []byte{}, fmt.Errorf("operation not supported on external signers")
+}
+
+// SignData signs keccak256(data). The mimetype parameter describes the type of data being signed
+func (api *ExternalSigner) SignData(account accounts.Account, mimeType string, data []byte) ([]byte, error) {
+	var res hexutil.Bytes
+	var signAddress = common.NewMixedcaseAddress(account.Address)
+	if err := api.client.Call(&res, "account_signData",
+		mimeType,
+		&signAddress, // Need to use the pointer here, because of how MarshalJSON is defined
+		hexutil.Encode(data)); err != nil {
+		return nil, err
+	}
+	// If V is on 27/28-form, convert to to 0/1 for Clique
+	if mimeType == accounts.MimetypeClique && (res[64] == 27 || res[64] == 28) {
+		res[64] -= 27 // Transform V from 27/28 to 0/1 for Clique use
+	}
+	return res, nil
+}
+
+func (api *ExternalSigner) SignText(account accounts.Account, text []byte) ([]byte, error) {
+	var res hexutil.Bytes
+	var signAddress = common.NewMixedcaseAddress(account.Address)
+	if err := api.client.Call(&res, "account_signData",
+		accounts.MimetypeTextPlain,
+		&signAddress, // Need to use the pointer here, because of how MarshalJSON is defined
+		hexutil.Encode(text)); err != nil {
+		return nil, err
+	}
+	return res, nil
+}
+
+func (api *ExternalSigner) SignTx(account accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	res := ethapi.SignTransactionResult{}
+	data := hexutil.Bytes(tx.Data())
+	var to *common.MixedcaseAddress
+	if tx.To() != nil {
+		t := common.NewMixedcaseAddress(*tx.To())
+		to = &t
+	}
+	args := &core.SendTxArgs{
+		Data:     &data,
+		Nonce:    hexutil.Uint64(tx.Nonce()),
+		Value:    hexutil.Big(*tx.Value()),
+		Gas:      hexutil.Uint64(tx.Gas()),
+		GasPrice: hexutil.Big(*tx.GasPrice()),
+		To:       to,
+		From:     common.NewMixedcaseAddress(account.Address),
+	}
+	if err := api.client.Call(&res, "account_signTransaction", args); err != nil {
+		return nil, err
+	}
+	return res.Tx, nil
+}
+
+func (api *ExternalSigner) SignTextWithPassphrase(account accounts.Account, passphrase string, text []byte) ([]byte, error) {
+	return []byte{}, fmt.Errorf("password-operations not supported on external signers")
+}
+
+func (api *ExternalSigner) SignTxWithPassphrase(account accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	return nil, fmt.Errorf("password-operations not supported on external signers")
+}
+func (api *ExternalSigner) SignDataWithPassphrase(account accounts.Account, passphrase, mimeType string, data []byte) ([]byte, error) {
+	return nil, fmt.Errorf("password-operations not supported on external signers")
+}
+
+func (api *ExternalSigner) listAccounts() ([]common.Address, error) {
+	var res []common.Address
+	if err := api.client.Call(&res, "account_list"); err != nil {
+		return nil, err
+	}
+	return res, nil
+}
+
+func (api *ExternalSigner) pingVersion() (string, error) {
+	var v string
+	if err := api.client.Call(&v, "account_version"); err != nil {
+		return "", err
+	}
+	return v, nil
+}
diff --git a/accounts/hd.go b/accounts/hd.go
new file mode 100644
index 0000000..75c4761
--- /dev/null
+++ b/accounts/hd.go
@@ -0,0 +1,152 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"math"
+	"math/big"
+	"strings"
+)
+
+// DefaultRootDerivationPath is the root path to which custom derivation endpoints
+// are appended. As such, the first account will be at m/44'/60'/0'/0, the second
+// at m/44'/60'/0'/1, etc.
+var DefaultRootDerivationPath = DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0}
+
+// DefaultBaseDerivationPath is the base path from which custom derivation endpoints
+// are incremented. As such, the first account will be at m/44'/60'/0'/0/0, the second
+// at m/44'/60'/0'/0/1, etc.
+var DefaultBaseDerivationPath = DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0, 0}
+
+// LegacyLedgerBaseDerivationPath is the legacy base path from which custom derivation
+// endpoints are incremented. As such, the first account will be at m/44'/60'/0'/0, the
+// second at m/44'/60'/0'/1, etc.
+var LegacyLedgerBaseDerivationPath = DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0}
+
+// DerivationPath represents the computer friendly version of a hierarchical
+// deterministic wallet account derivaion path.
+//
+// The BIP-32 spec https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki
+// defines derivation paths to be of the form:
+//
+//   m / purpose' / coin_type' / account' / change / address_index
+//
+// The BIP-44 spec https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki
+// defines that the `purpose` be 44' (or 0x8000002C) for crypto currencies, and
+// SLIP-44 https://github.com/satoshilabs/slips/blob/master/slip-0044.md assigns
+// the `coin_type` 60' (or 0x8000003C) to Ethereum.
+//
+// The root path for Ethereum is m/44'/60'/0'/0 according to the specification
+// from https://github.com/ethereum/EIPs/issues/84, albeit it's not set in stone
+// yet whether accounts should increment the last component or the children of
+// that. We will go with the simpler approach of incrementing the last component.
+type DerivationPath []uint32
+
+// ParseDerivationPath converts a user specified derivation path string to the
+// internal binary representation.
+//
+// Full derivation paths need to start with the `m/` prefix, relative derivation
+// paths (which will get appended to the default root path) must not have prefixes
+// in front of the first element. Whitespace is ignored.
+func ParseDerivationPath(path string) (DerivationPath, error) {
+	var result DerivationPath
+
+	// Handle absolute or relative paths
+	components := strings.Split(path, "/")
+	switch {
+	case len(components) == 0:
+		return nil, errors.New("empty derivation path")
+
+	case strings.TrimSpace(components[0]) == "":
+		return nil, errors.New("ambiguous path: use 'm/' prefix for absolute paths, or no leading '/' for relative ones")
+
+	case strings.TrimSpace(components[0]) == "m":
+		components = components[1:]
+
+	default:
+		result = append(result, DefaultRootDerivationPath...)
+	}
+	// All remaining components are relative, append one by one
+	if len(components) == 0 {
+		return nil, errors.New("empty derivation path") // Empty relative paths
+	}
+	for _, component := range components {
+		// Ignore any user added whitespace
+		component = strings.TrimSpace(component)
+		var value uint32
+
+		// Handle hardened paths
+		if strings.HasSuffix(component, "'") {
+			value = 0x80000000
+			component = strings.TrimSpace(strings.TrimSuffix(component, "'"))
+		}
+		// Handle the non hardened component
+		bigval, ok := new(big.Int).SetString(component, 0)
+		if !ok {
+			return nil, fmt.Errorf("invalid component: %s", component)
+		}
+		max := math.MaxUint32 - value
+		if bigval.Sign() < 0 || bigval.Cmp(big.NewInt(int64(max))) > 0 {
+			if value == 0 {
+				return nil, fmt.Errorf("component %v out of allowed range [0, %d]", bigval, max)
+			}
+			return nil, fmt.Errorf("component %v out of allowed hardened range [0, %d]", bigval, max)
+		}
+		value += uint32(bigval.Uint64())
+
+		// Append and repeat
+		result = append(result, value)
+	}
+	return result, nil
+}
+
+// String implements the stringer interface, converting a binary derivation path
+// to its canonical representation.
+func (path DerivationPath) String() string {
+	result := "m"
+	for _, component := range path {
+		var hardened bool
+		if component >= 0x80000000 {
+			component -= 0x80000000
+			hardened = true
+		}
+		result = fmt.Sprintf("%s/%d", result, component)
+		if hardened {
+			result += "'"
+		}
+	}
+	return result
+}
+
+// MarshalJSON turns a derivation path into its json-serialized string
+func (path DerivationPath) MarshalJSON() ([]byte, error) {
+	return json.Marshal(path.String())
+}
+
+// UnmarshalJSON a json-serialized string back into a derivation path
+func (path *DerivationPath) UnmarshalJSON(b []byte) error {
+	var dp string
+	var err error
+	if err = json.Unmarshal(b, &dp); err != nil {
+		return err
+	}
+	*path, err = ParseDerivationPath(dp)
+	return err
+}
diff --git a/accounts/keystore/account_cache.go b/accounts/keystore/account_cache.go
new file mode 100644
index 0000000..2067ccb
--- /dev/null
+++ b/accounts/keystore/account_cache.go
@@ -0,0 +1,301 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/ava-labs/coreth/accounts"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/log"
+	mapset "github.com/deckarep/golang-set"
+)
+
+// Minimum amount of time between cache reloads. This limit applies if the platform does
+// not support change notifications. It also applies if the keystore directory does not
+// exist yet, the code will attempt to create a watcher at most this often.
+const minReloadInterval = 2 * time.Second
+
+type accountsByURL []accounts.Account
+
+func (s accountsByURL) Len() int           { return len(s) }
+func (s accountsByURL) Less(i, j int) bool { return s[i].URL.Cmp(s[j].URL) < 0 }
+func (s accountsByURL) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+
+// AmbiguousAddrError is returned when attempting to unlock
+// an address for which more than one file exists.
+type AmbiguousAddrError struct {
+	Addr    common.Address
+	Matches []accounts.Account
+}
+
+func (err *AmbiguousAddrError) Error() string {
+	files := ""
+	for i, a := range err.Matches {
+		files += a.URL.Path
+		if i < len(err.Matches)-1 {
+			files += ", "
+		}
+	}
+	return fmt.Sprintf("multiple keys match address (%s)", files)
+}
+
+// accountCache is a live index of all accounts in the keystore.
+type accountCache struct {
+	keydir   string
+	watcher  *watcher
+	mu       sync.Mutex
+	all      accountsByURL
+	byAddr   map[common.Address][]accounts.Account
+	throttle *time.Timer
+	notify   chan struct{}
+	fileC    fileCache
+}
+
+func newAccountCache(keydir string) (*accountCache, chan struct{}) {
+	ac := &accountCache{
+		keydir: keydir,
+		byAddr: make(map[common.Address][]accounts.Account),
+		notify: make(chan struct{}, 1),
+		fileC:  fileCache{all: mapset.NewThreadUnsafeSet()},
+	}
+	ac.watcher = newWatcher(ac)
+	return ac, ac.notify
+}
+
+func (ac *accountCache) accounts() []accounts.Account {
+	ac.maybeReload()
+	ac.mu.Lock()
+	defer ac.mu.Unlock()
+	cpy := make([]accounts.Account, len(ac.all))
+	copy(cpy, ac.all)
+	return cpy
+}
+
+func (ac *accountCache) hasAddress(addr common.Address) bool {
+	ac.maybeReload()
+	ac.mu.Lock()
+	defer ac.mu.Unlock()
+	return len(ac.byAddr[addr]) > 0
+}
+
+func (ac *accountCache) add(newAccount accounts.Account) {
+	ac.mu.Lock()
+	defer ac.mu.Unlock()
+
+	i := sort.Search(len(ac.all), func(i int) bool { return ac.all[i].URL.Cmp(newAccount.URL) >= 0 })
+	if i < len(ac.all) && ac.all[i] == newAccount {
+		return
+	}
+	// newAccount is not in the cache.
+	ac.all = append(ac.all, accounts.Account{})
+	copy(ac.all[i+1:], ac.all[i:])
+	ac.all[i] = newAccount
+	ac.byAddr[newAccount.Address] = append(ac.byAddr[newAccount.Address], newAccount)
+}
+
+// note: removed needs to be unique here (i.e. both File and Address must be set).
+func (ac *accountCache) delete(removed accounts.Account) {
+	ac.mu.Lock()
+	defer ac.mu.Unlock()
+
+	ac.all = removeAccount(ac.all, removed)
+	if ba := removeAccount(ac.byAddr[removed.Address], removed); len(ba) == 0 {
+		delete(ac.byAddr, removed.Address)
+	} else {
+		ac.byAddr[removed.Address] = ba
+	}
+}
+
+// deleteByFile removes an account referenced by the given path.
+func (ac *accountCache) deleteByFile(path string) {
+	ac.mu.Lock()
+	defer ac.mu.Unlock()
+	i := sort.Search(len(ac.all), func(i int) bool { return ac.all[i].URL.Path >= path })
+
+	if i < len(ac.all) && ac.all[i].URL.Path == path {
+		removed := ac.all[i]
+		ac.all = append(ac.all[:i], ac.all[i+1:]...)
+		if ba := removeAccount(ac.byAddr[removed.Address], removed); len(ba) == 0 {
+			delete(ac.byAddr, removed.Address)
+		} else {
+			ac.byAddr[removed.Address] = ba
+		}
+	}
+}
+
+func removeAccount(slice []accounts.Account, elem accounts.Account) []accounts.Account {
+	for i := range slice {
+		if slice[i] == elem {
+			return append(slice[:i], slice[i+1:]...)
+		}
+	}
+	return slice
+}
+
+// find returns the cached account for address if there is a unique match.
+// The exact matching rules are explained by the documentation of accounts.Account.
+// Callers must hold ac.mu.
+func (ac *accountCache) find(a accounts.Account) (accounts.Account, error) {
+	// Limit search to address candidates if possible.
+	matches := ac.all
+	if (a.Address != common.Address{}) {
+		matches = ac.byAddr[a.Address]
+	}
+	if a.URL.Path != "" {
+		// If only the basename is specified, complete the path.
+		if !strings.ContainsRune(a.URL.Path, filepath.Separator) {
+			a.URL.Path = filepath.Join(ac.keydir, a.URL.Path)
+		}
+		for i := range matches {
+			if matches[i].URL == a.URL {
+				return matches[i], nil
+			}
+		}
+		if (a.Address == common.Address{}) {
+			return accounts.Account{}, ErrNoMatch
+		}
+	}
+	switch len(matches) {
+	case 1:
+		return matches[0], nil
+	case 0:
+		return accounts.Account{}, ErrNoMatch
+	default:
+		err := &AmbiguousAddrError{Addr: a.Address, Matches: make([]accounts.Account, len(matches))}
+		copy(err.Matches, matches)
+		sort.Sort(accountsByURL(err.Matches))
+		return accounts.Account{}, err
+	}
+}
+
+func (ac *accountCache) maybeReload() {
+	ac.mu.Lock()
+
+	if ac.watcher.running {
+		ac.mu.Unlock()
+		return // A watcher is running and will keep the cache up-to-date.
+	}
+	if ac.throttle == nil {
+		ac.throttle = time.NewTimer(0)
+	} else {
+		select {
+		case <-ac.throttle.C:
+		default:
+			ac.mu.Unlock()
+			return // The cache was reloaded recently.
+		}
+	}
+	// No watcher running, start it.
+	ac.watcher.start()
+	ac.throttle.Reset(minReloadInterval)
+	ac.mu.Unlock()
+	ac.scanAccounts()
+}
+
+func (ac *accountCache) close() {
+	ac.mu.Lock()
+	ac.watcher.close()
+	if ac.throttle != nil {
+		ac.throttle.Stop()
+	}
+	if ac.notify != nil {
+		close(ac.notify)
+		ac.notify = nil
+	}
+	ac.mu.Unlock()
+}
+
+// scanAccounts checks if any changes have occurred on the filesystem, and
+// updates the account cache accordingly
+func (ac *accountCache) scanAccounts() error {
+	// Scan the entire folder metadata for file changes
+	creates, deletes, updates, err := ac.fileC.scan(ac.keydir)
+	if err != nil {
+		log.Debug("Failed to reload keystore contents", "err", err)
+		return err
+	}
+	if creates.Cardinality() == 0 && deletes.Cardinality() == 0 && updates.Cardinality() == 0 {
+		return nil
+	}
+	// Create a helper method to scan the contents of the key files
+	var (
+		buf = new(bufio.Reader)
+		key struct {
+			Address string `json:"address"`
+		}
+	)
+	readAccount := func(path string) *accounts.Account {
+		fd, err := os.Open(path)
+		if err != nil {
+			log.Trace("Failed to open keystore file", "path", path, "err", err)
+			return nil
+		}
+		defer fd.Close()
+		buf.Reset(fd)
+		// Parse the address.
+		key.Address = ""
+		err = json.NewDecoder(buf).Decode(&key)
+		addr := common.HexToAddress(key.Address)
+		switch {
+		case err != nil:
+			log.Debug("Failed to decode keystore key", "path", path, "err", err)
+		case (addr == common.Address{}):
+			log.Debug("Failed to decode keystore key", "path", path, "err", "missing or zero address")
+		default:
+			return &accounts.Account{
+				Address: addr,
+				URL:     accounts.URL{Scheme: KeyStoreScheme, Path: path},
+			}
+		}
+		return nil
+	}
+	// Process all the file diffs
+	start := time.Now()
+
+	for _, p := range creates.ToSlice() {
+		if a := readAccount(p.(string)); a != nil {
+			ac.add(*a)
+		}
+	}
+	for _, p := range deletes.ToSlice() {
+		ac.deleteByFile(p.(string))
+	}
+	for _, p := range updates.ToSlice() {
+		path := p.(string)
+		ac.deleteByFile(path)
+		if a := readAccount(path); a != nil {
+			ac.add(*a)
+		}
+	}
+	end := time.Now()
+
+	select {
+	case ac.notify <- struct{}{}:
+	default:
+	}
+	log.Trace("Handled keystore changes", "time", end.Sub(start))
+	return nil
+}
diff --git a/accounts/keystore/file_cache.go b/accounts/keystore/file_cache.go
new file mode 100644
index 0000000..ac87f0c
--- /dev/null
+++ b/accounts/keystore/file_cache.go
@@ -0,0 +1,102 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	mapset "github.com/deckarep/golang-set"
+	"github.com/ava-labs/go-ethereum/log"
+)
+
+// fileCache is a cache of files seen during scan of keystore.
+type fileCache struct {
+	all     mapset.Set // Set of all files from the keystore folder
+	lastMod time.Time  // Last time instance when a file was modified
+	mu      sync.RWMutex
+}
+
+// scan performs a new scan on the given directory, compares against the already
+// cached filenames, and returns file sets: creates, deletes, updates.
+func (fc *fileCache) scan(keyDir string) (mapset.Set, mapset.Set, mapset.Set, error) {
+	t0 := time.Now()
+
+	// List all the failes from the keystore folder
+	files, err := ioutil.ReadDir(keyDir)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+	t1 := time.Now()
+
+	fc.mu.Lock()
+	defer fc.mu.Unlock()
+
+	// Iterate all the files and gather their metadata
+	all := mapset.NewThreadUnsafeSet()
+	mods := mapset.NewThreadUnsafeSet()
+
+	var newLastMod time.Time
+	for _, fi := range files {
+		path := filepath.Join(keyDir, fi.Name())
+		// Skip any non-key files from the folder
+		if nonKeyFile(fi) {
+			log.Trace("Ignoring file on account scan", "path", path)
+			continue
+		}
+		// Gather the set of all and fresly modified files
+		all.Add(path)
+
+		modified := fi.ModTime()
+		if modified.After(fc.lastMod) {
+			mods.Add(path)
+		}
+		if modified.After(newLastMod) {
+			newLastMod = modified
+		}
+	}
+	t2 := time.Now()
+
+	// Update the tracked files and return the three sets
+	deletes := fc.all.Difference(all)   // Deletes = previous - current
+	creates := all.Difference(fc.all)   // Creates = current - previous
+	updates := mods.Difference(creates) // Updates = modified - creates
+
+	fc.all, fc.lastMod = all, newLastMod
+	t3 := time.Now()
+
+	// Report on the scanning stats and return
+	log.Debug("FS scan times", "list", t1.Sub(t0), "set", t2.Sub(t1), "diff", t3.Sub(t2))
+	return creates, deletes, updates, nil
+}
+
+// nonKeyFile ignores editor backups, hidden files and folders/symlinks.
+func nonKeyFile(fi os.FileInfo) bool {
+	// Skip editor backups and UNIX-style hidden files.
+	if strings.HasSuffix(fi.Name(), "~") || strings.HasPrefix(fi.Name(), ".") {
+		return true
+	}
+	// Skip misc special files, directories (yes, symlinks too).
+	if fi.IsDir() || fi.Mode()&os.ModeType != 0 {
+		return true
+	}
+	return false
+}
diff --git a/accounts/keystore/key.go b/accounts/keystore/key.go
new file mode 100644
index 0000000..3654daa
--- /dev/null
+++ b/accounts/keystore/key.go
@@ -0,0 +1,232 @@
+// Copyright 2014 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"bytes"
+	"crypto/ecdsa"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/ava-labs/coreth/accounts"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/crypto"
+	"github.com/pborman/uuid"
+)
+
+const (
+	version = 3
+)
+
+type Key struct {
+	Id uuid.UUID // Version 4 "random" for unique id not derived from key data
+	// to simplify lookups we also store the address
+	Address common.Address
+	// we only store privkey as pubkey/address can be derived from it
+	// privkey in this struct is always in plaintext
+	PrivateKey *ecdsa.PrivateKey
+}
+
+type keyStore interface {
+	// Loads and decrypts the key from disk.
+	GetKey(addr common.Address, filename string, auth string) (*Key, error)
+	// Writes and encrypts the key.
+	StoreKey(filename string, k *Key, auth string) error
+	// Joins filename with the key directory unless it is already absolute.
+	JoinPath(filename string) string
+}
+
+type plainKeyJSON struct {
+	Address    string `json:"address"`
+	PrivateKey string `json:"privatekey"`
+	Id         string `json:"id"`
+	Version    int    `json:"version"`
+}
+
+type encryptedKeyJSONV3 struct {
+	Address string     `json:"address"`
+	Crypto  CryptoJSON `json:"crypto"`
+	Id      string     `json:"id"`
+	Version int        `json:"version"`
+}
+
+type encryptedKeyJSONV1 struct {
+	Address string     `json:"address"`
+	Crypto  CryptoJSON `json:"crypto"`
+	Id      string     `json:"id"`
+	Version string     `json:"version"`
+}
+
+type CryptoJSON struct {
+	Cipher       string                 `json:"cipher"`
+	CipherText   string                 `json:"ciphertext"`
+	CipherParams cipherparamsJSON       `json:"cipherparams"`
+	KDF          string                 `json:"kdf"`
+	KDFParams    map[string]interface{} `json:"kdfparams"`
+	MAC          string                 `json:"mac"`
+}
+
+type cipherparamsJSON struct {
+	IV string `json:"iv"`
+}
+
+func (k *Key) MarshalJSON() (j []byte, err error) {
+	jStruct := plainKeyJSON{
+		hex.EncodeToString(k.Address[:]),
+		hex.EncodeToString(crypto.FromECDSA(k.PrivateKey)),
+		k.Id.String(),
+		version,
+	}
+	j, err = json.Marshal(jStruct)
+	return j, err
+}
+
+func (k *Key) UnmarshalJSON(j []byte) (err error) {
+	keyJSON := new(plainKeyJSON)
+	err = json.Unmarshal(j, &keyJSON)
+	if err != nil {
+		return err
+	}
+
+	u := new(uuid.UUID)
+	*u = uuid.Parse(keyJSON.Id)
+	k.Id = *u
+	addr, err := hex.DecodeString(keyJSON.Address)
+	if err != nil {
+		return err
+	}
+	privkey, err := crypto.HexToECDSA(keyJSON.PrivateKey)
+	if err != nil {
+		return err
+	}
+
+	k.Address = common.BytesToAddress(addr)
+	k.PrivateKey = privkey
+
+	return nil
+}
+
+func newKeyFromECDSA(privateKeyECDSA *ecdsa.PrivateKey) *Key {
+	id := uuid.NewRandom()
+	key := &Key{
+		Id:         id,
+		Address:    crypto.PubkeyToAddress(privateKeyECDSA.PublicKey),
+		PrivateKey: privateKeyECDSA,
+	}
+	return key
+}
+
+// NewKeyForDirectICAP generates a key whose address fits into < 155 bits so it can fit
+// into the Direct ICAP spec. for simplicity and easier compatibility with other libs, we
+// retry until the first byte is 0.
+func NewKeyForDirectICAP(rand io.Reader) *Key {
+	randBytes := make([]byte, 64)
+	_, err := rand.Read(randBytes)
+	if err != nil {
+		panic("key generation: could not read from random source: " + err.Error())
+	}
+	reader := bytes.NewReader(randBytes)
+	privateKeyECDSA, err := ecdsa.GenerateKey(crypto.S256(), reader)
+	if err != nil {
+		panic("key generation: ecdsa.GenerateKey failed: " + err.Error())
+	}
+	key := newKeyFromECDSA(privateKeyECDSA)
+	if !strings.HasPrefix(key.Address.Hex(), "0x00") {
+		return NewKeyForDirectICAP(rand)
+	}
+	return key
+}
+
+func newKey(rand io.Reader) (*Key, error) {
+	privateKeyECDSA, err := ecdsa.GenerateKey(crypto.S256(), rand)
+	if err != nil {
+		return nil, err
+	}
+	return newKeyFromECDSA(privateKeyECDSA), nil
+}
+
+func storeNewKey(ks keyStore, rand io.Reader, auth string) (*Key, accounts.Account, error) {
+	key, err := newKey(rand)
+	if err != nil {
+		return nil, accounts.Account{}, err
+	}
+	a := accounts.Account{
+		Address: key.Address,
+		URL:     accounts.URL{Scheme: KeyStoreScheme, Path: ks.JoinPath(keyFileName(key.Address))},
+	}
+	if err := ks.StoreKey(a.URL.Path, key, auth); err != nil {
+		zeroKey(key.PrivateKey)
+		return nil, a, err
+	}
+	return key, a, err
+}
+
+func writeTemporaryKeyFile(file string, content []byte) (string, error) {
+	// Create the keystore directory with appropriate permissions
+	// in case it is not present yet.
+	const dirPerm = 0700
+	if err := os.MkdirAll(filepath.Dir(file), dirPerm); err != nil {
+		return "", err
+	}
+	// Atomic write: create a temporary hidden file first
+	// then move it into place. TempFile assigns mode 0600.
+	f, err := ioutil.TempFile(filepath.Dir(file), "."+filepath.Base(file)+".tmp")
+	if err != nil {
+		return "", err
+	}
+	if _, err := f.Write(content); err != nil {
+		f.Close()
+		os.Remove(f.Name())
+		return "", err
+	}
+	f.Close()
+	return f.Name(), nil
+}
+
+func writeKeyFile(file string, content []byte) error {
+	name, err := writeTemporaryKeyFile(file, content)
+	if err != nil {
+		return err
+	}
+	return os.Rename(name, file)
+}
+
+// keyFileName implements the naming convention for keyfiles:
+// UTC--<created_at UTC ISO8601>-<address hex>
+func keyFileName(keyAddr common.Address) string {
+	ts := time.Now().UTC()
+	return fmt.Sprintf("UTC--%s--%s", toISO8601(ts), hex.EncodeToString(keyAddr[:]))
+}
+
+func toISO8601(t time.Time) string {
+	var tz string
+	name, offset := t.Zone()
+	if name == "UTC" {
+		tz = "Z"
+	} else {
+		tz = fmt.Sprintf("%03d00", offset/3600)
+	}
+	return fmt.Sprintf("%04d-%02d-%02dT%02d-%02d-%02d.%09d%s",
+		t.Year(), t.Month(), t.Day(), t.Hour(), t.Minute(), t.Second(), t.Nanosecond(), tz)
+}
diff --git a/accounts/keystore/keystore.go b/accounts/keystore/keystore.go
new file mode 100644
index 0000000..a3ce33f
--- /dev/null
+++ b/accounts/keystore/keystore.go
@@ -0,0 +1,495 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package keystore implements encrypted storage of secp256k1 private keys.
+//
+// Keys are stored as encrypted JSON files according to the Web3 Secret Storage specification.
+// See https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition for more information.
+package keystore
+
+import (
+	"crypto/ecdsa"
+	crand "crypto/rand"
+	"errors"
+	"fmt"
+	"math/big"
+	"os"
+	"path/filepath"
+	"reflect"
+	"runtime"
+	"sync"
+	"time"
+
+	"github.com/ava-labs/coreth/accounts"
+	"github.com/ava-labs/coreth/core/types"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/crypto"
+	"github.com/ava-labs/go-ethereum/event"
+)
+
+var (
+	ErrLocked  = accounts.NewAuthNeededError("password or unlock")
+	ErrNoMatch = errors.New("no key for given address or file")
+	ErrDecrypt = errors.New("could not decrypt key with given password")
+)
+
+// KeyStoreType is the reflect type of a keystore backend.
+var KeyStoreType = reflect.TypeOf(&KeyStore{})
+
+// KeyStoreScheme is the protocol scheme prefixing account and wallet URLs.
+const KeyStoreScheme = "keystore"
+
+// Maximum time between wallet refreshes (if filesystem notifications don't work).
+const walletRefreshCycle = 3 * time.Second
+
+// KeyStore manages a key storage directory on disk.
+type KeyStore struct {
+	storage  keyStore                     // Storage backend, might be cleartext or encrypted
+	cache    *accountCache                // In-memory account cache over the filesystem storage
+	changes  chan struct{}                // Channel receiving change notifications from the cache
+	unlocked map[common.Address]*unlocked // Currently unlocked account (decrypted private keys)
+
+	wallets     []accounts.Wallet       // Wallet wrappers around the individual key files
+	updateFeed  event.Feed              // Event feed to notify wallet additions/removals
+	updateScope event.SubscriptionScope // Subscription scope tracking current live listeners
+	updating    bool                    // Whether the event notification loop is running
+
+	mu sync.RWMutex
+}
+
+type unlocked struct {
+	*Key
+	abort chan struct{}
+}
+
+// NewKeyStore creates a keystore for the given directory.
+func NewKeyStore(keydir string, scryptN, scryptP int) *KeyStore {
+	keydir, _ = filepath.Abs(keydir)
+	ks := &KeyStore{storage: &keyStorePassphrase{keydir, scryptN, scryptP, false}}
+	ks.init(keydir)
+	return ks
+}
+
+// NewPlaintextKeyStore creates a keystore for the given directory.
+// Deprecated: Use NewKeyStore.
+func NewPlaintextKeyStore(keydir string) *KeyStore {
+	keydir, _ = filepath.Abs(keydir)
+	ks := &KeyStore{storage: &keyStorePlain{keydir}}
+	ks.init(keydir)
+	return ks
+}
+
+func (ks *KeyStore) init(keydir string) {
+	// Lock the mutex since the account cache might call back with events
+	ks.mu.Lock()
+	defer ks.mu.Unlock()
+
+	// Initialize the set of unlocked keys and the account cache
+	ks.unlocked = make(map[common.Address]*unlocked)
+	ks.cache, ks.changes = newAccountCache(keydir)
+
+	// TODO: In order for this finalizer to work, there must be no references
+	// to ks. addressCache doesn't keep a reference but unlocked keys do,
+	// so the finalizer will not trigger until all timed unlocks have expired.
+	runtime.SetFinalizer(ks, func(m *KeyStore) {
+		m.cache.close()
+	})
+	// Create the initial list of wallets from the cache
+	accs := ks.cache.accounts()
+	ks.wallets = make([]accounts.Wallet, len(accs))
+	for i := 0; i < len(accs); i++ {
+		ks.wallets[i] = &keystoreWallet{account: accs[i], keystore: ks}
+	}
+}
+
+// Wallets implements accounts.Backend, returning all single-key wallets from the
+// keystore directory.
+func (ks *KeyStore) Wallets() []accounts.Wallet {
+	// Make sure the list of wallets is in sync with the account cache
+	ks.refreshWallets()
+
+	ks.mu.RLock()
+	defer ks.mu.RUnlock()
+
+	cpy := make([]accounts.Wallet, len(ks.wallets))
+	copy(cpy, ks.wallets)
+	return cpy
+}
+
+// refreshWallets retrieves the current account list and based on that does any
+// necessary wallet refreshes.
+func (ks *KeyStore) refreshWallets() {
+	// Retrieve the current list of accounts
+	ks.mu.Lock()
+	accs := ks.cache.accounts()
+
+	// Transform the current list of wallets into the new one
+	var (
+		wallets = make([]accounts.Wallet, 0, len(accs))
+		events  []accounts.WalletEvent
+	)
+
+	for _, account := range accs {
+		// Drop wallets while they were in front of the next account
+		for len(ks.wallets) > 0 && ks.wallets[0].URL().Cmp(account.URL) < 0 {
+			events = append(events, accounts.WalletEvent{Wallet: ks.wallets[0], Kind: accounts.WalletDropped})
+			ks.wallets = ks.wallets[1:]
+		}
+		// If there are no more wallets or the account is before the next, wrap new wallet
+		if len(ks.wallets) == 0 || ks.wallets[0].URL().Cmp(account.URL) > 0 {
+			wallet := &keystoreWallet{account: account, keystore: ks}
+
+			events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletArrived})
+			wallets = append(wallets, wallet)
+			continue
+		}
+		// If the account is the same as the first wallet, keep it
+		if ks.wallets[0].Accounts()[0] == account {
+			wallets = append(wallets, ks.wallets[0])
+			ks.wallets = ks.wallets[1:]
+			continue
+		}
+	}
+	// Drop any leftover wallets and set the new batch
+	for _, wallet := range ks.wallets {
+		events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped})
+	}
+	ks.wallets = wallets
+	ks.mu.Unlock()
+
+	// Fire all wallet events and return
+	for _, event := range events {
+		ks.updateFeed.Send(event)
+	}
+}
+
+// Subscribe implements accounts.Backend, creating an async subscription to
+// receive notifications on the addition or removal of keystore wallets.
+func (ks *KeyStore) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription {
+	// We need the mutex to reliably start/stop the update loop
+	ks.mu.Lock()
+	defer ks.mu.Unlock()
+
+	// Subscribe the caller and track the subscriber count
+	sub := ks.updateScope.Track(ks.updateFeed.Subscribe(sink))
+
+	// Subscribers require an active notification loop, start it
+	if !ks.updating {
+		ks.updating = true
+		go ks.updater()
+	}
+	return sub
+}
+
+// updater is responsible for maintaining an up-to-date list of wallets stored in
+// the keystore, and for firing wallet addition/removal events. It listens for
+// account change events from the underlying account cache, and also periodically
+// forces a manual refresh (only triggers for systems where the filesystem notifier
+// is not running).
+func (ks *KeyStore) updater() {
+	for {
+		// Wait for an account update or a refresh timeout
+		select {
+		case <-ks.changes:
+		case <-time.After(walletRefreshCycle):
+		}
+		// Run the wallet refresher
+		ks.refreshWallets()
+
+		// If all our subscribers left, stop the updater
+		ks.mu.Lock()
+		if ks.updateScope.Count() == 0 {
+			ks.updating = false
+			ks.mu.Unlock()
+			return
+		}
+		ks.mu.Unlock()
+	}
+}
+
+// HasAddress reports whether a key with the given address is present.
+func (ks *KeyStore) HasAddress(addr common.Address) bool {
+	return ks.cache.hasAddress(addr)
+}
+
+// Accounts returns all key files present in the directory.
+func (ks *KeyStore) Accounts() []accounts.Account {
+	return ks.cache.accounts()
+}
+
+// Delete deletes the key matched by account if the passphrase is correct.
+// If the account contains no filename, the address must match a unique key.
+func (ks *KeyStore) Delete(a accounts.Account, passphrase string) error {
+	// Decrypting the key isn't really necessary, but we do
+	// it anyway to check the password and zero out the key
+	// immediately afterwards.
+	a, key, err := ks.getDecryptedKey(a, passphrase)
+	if key != nil {
+		zeroKey(key.PrivateKey)
+	}
+	if err != nil {
+		return err
+	}
+	// The order is crucial here. The key is dropped from the
+	// cache after the file is gone so that a reload happening in
+	// between won't insert it into the cache again.
+	err = os.Remove(a.URL.Path)
+	if err == nil {
+		ks.cache.delete(a)
+		ks.refreshWallets()
+	}
+	return err
+}
+
+// SignHash calculates a ECDSA signature for the given hash. The produced
+// signature is in the [R || S || V] format where V is 0 or 1.
+func (ks *KeyStore) SignHash(a accounts.Account, hash []byte) ([]byte, error) {
+	// Look up the key to sign with and abort if it cannot be found
+	ks.mu.RLock()
+	defer ks.mu.RUnlock()
+
+	unlockedKey, found := ks.unlocked[a.Address]
+	if !found {
+		return nil, ErrLocked
+	}
+	// Sign the hash using plain ECDSA operations
+	return crypto.Sign(hash, unlockedKey.PrivateKey)
+}
+
+// SignTx signs the given transaction with the requested account.
+func (ks *KeyStore) SignTx(a accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	// Look up the key to sign with and abort if it cannot be found
+	ks.mu.RLock()
+	defer ks.mu.RUnlock()
+
+	unlockedKey, found := ks.unlocked[a.Address]
+	if !found {
+		return nil, ErrLocked
+	}
+	// Depending on the presence of the chain ID, sign with EIP155 or homestead
+	if chainID != nil {
+		return types.SignTx(tx, types.NewEIP155Signer(chainID), unlockedKey.PrivateKey)
+	}
+	return types.SignTx(tx, types.HomesteadSigner{}, unlockedKey.PrivateKey)
+}
+
+// SignHashWithPassphrase signs hash if the private key matching the given address
+// can be decrypted with the given passphrase. The produced signature is in the
+// [R || S || V] format where V is 0 or 1.
+func (ks *KeyStore) SignHashWithPassphrase(a accounts.Account, passphrase string, hash []byte) (signature []byte, err error) {
+	_, key, err := ks.getDecryptedKey(a, passphrase)
+	if err != nil {
+		return nil, err
+	}
+	defer zeroKey(key.PrivateKey)
+	return crypto.Sign(hash, key.PrivateKey)
+}
+
+// SignTxWithPassphrase signs the transaction if the private key matching the
+// given address can be decrypted with the given passphrase.
+func (ks *KeyStore) SignTxWithPassphrase(a accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	_, key, err := ks.getDecryptedKey(a, passphrase)
+	if err != nil {
+		return nil, err
+	}
+	defer zeroKey(key.PrivateKey)
+
+	// Depending on the presence of the chain ID, sign with EIP155 or homestead
+	if chainID != nil {
+		return types.SignTx(tx, types.NewEIP155Signer(chainID), key.PrivateKey)
+	}
+	return types.SignTx(tx, types.HomesteadSigner{}, key.PrivateKey)
+}
+
+// Unlock unlocks the given account indefinitely.
+func (ks *KeyStore) Unlock(a accounts.Account, passphrase string) error {
+	return ks.TimedUnlock(a, passphrase, 0)
+}
+
+// Lock removes the private key with the given address from memory.
+func (ks *KeyStore) Lock(addr common.Address) error {
+	ks.mu.Lock()
+	if unl, found := ks.unlocked[addr]; found {
+		ks.mu.Unlock()
+		ks.expire(addr, unl, time.Duration(0)*time.Nanosecond)
+	} else {
+		ks.mu.Unlock()
+	}
+	return nil
+}
+
+// TimedUnlock unlocks the given account with the passphrase. The account
+// stays unlocked for the duration of timeout. A timeout of 0 unlocks the account
+// until the program exits. The account must match a unique key file.
+//
+// If the account address is already unlocked for a duration, TimedUnlock extends or
+// shortens the active unlock timeout. If the address was previously unlocked
+// indefinitely the timeout is not altered.
+func (ks *KeyStore) TimedUnlock(a accounts.Account, passphrase string, timeout time.Duration) error {
+	a, key, err := ks.getDecryptedKey(a, passphrase)
+	if err != nil {
+		return err
+	}
+
+	ks.mu.Lock()
+	defer ks.mu.Unlock()
+	u, found := ks.unlocked[a.Address]
+	if found {
+		if u.abort == nil {
+			// The address was unlocked indefinitely, so unlocking
+			// it with a timeout would be confusing.
+			zeroKey(key.PrivateKey)
+			return nil
+		}
+		// Terminate the expire goroutine and replace it below.
+		close(u.abort)
+	}
+	if timeout > 0 {
+		u = &unlocked{Key: key, abort: make(chan struct{})}
+		go ks.expire(a.Address, u, timeout)
+	} else {
+		u = &unlocked{Key: key}
+	}
+	ks.unlocked[a.Address] = u
+	return nil
+}
+
+// Find resolves the given account into a unique entry in the keystore.
+func (ks *KeyStore) Find(a accounts.Account) (accounts.Account, error) {
+	ks.cache.maybeReload()
+	ks.cache.mu.Lock()
+	a, err := ks.cache.find(a)
+	ks.cache.mu.Unlock()
+	return a, err
+}
+
+func (ks *KeyStore) getDecryptedKey(a accounts.Account, auth string) (accounts.Account, *Key, error) {
+	a, err := ks.Find(a)
+	if err != nil {
+		return a, nil, err
+	}
+	key, err := ks.storage.GetKey(a.Address, a.URL.Path, auth)
+	return a, key, err
+}
+
+func (ks *KeyStore) expire(addr common.Address, u *unlocked, timeout time.Duration) {
+	t := time.NewTimer(timeout)
+	defer t.Stop()
+	select {
+	case <-u.abort:
+		// just quit
+	case <-t.C:
+		ks.mu.Lock()
+		// only drop if it's still the same key instance that dropLater
+		// was launched with. we can check that using pointer equality
+		// because the map stores a new pointer every time the key is
+		// unlocked.
+		if ks.unlocked[addr] == u {
+			zeroKey(u.PrivateKey)
+			delete(ks.unlocked, addr)
+		}
+		ks.mu.Unlock()
+	}
+}
+
+// NewAccount generates a new key and stores it into the key directory,
+// encrypting it with the passphrase.
+func (ks *KeyStore) NewAccount(passphrase string) (accounts.Account, error) {
+	_, account, err := storeNewKey(ks.storage, crand.Reader, passphrase)
+	if err != nil {
+		return accounts.Account{}, err
+	}
+	// Add the account to the cache immediately rather
+	// than waiting for file system notifications to pick it up.
+	ks.cache.add(account)
+	ks.refreshWallets()
+	return account, nil
+}
+
+// Export exports as a JSON key, encrypted with newPassphrase.
+func (ks *KeyStore) Export(a accounts.Account, passphrase, newPassphrase string) (keyJSON []byte, err error) {
+	_, key, err := ks.getDecryptedKey(a, passphrase)
+	if err != nil {
+		return nil, err
+	}
+	var N, P int
+	if store, ok := ks.storage.(*keyStorePassphrase); ok {
+		N, P = store.scryptN, store.scryptP
+	} else {
+		N, P = StandardScryptN, StandardScryptP
+	}
+	return EncryptKey(key, newPassphrase, N, P)
+}
+
+// Import stores the given encrypted JSON key into the key directory.
+func (ks *KeyStore) Import(keyJSON []byte, passphrase, newPassphrase string) (accounts.Account, error) {
+	key, err := DecryptKey(keyJSON, passphrase)
+	if key != nil && key.PrivateKey != nil {
+		defer zeroKey(key.PrivateKey)
+	}
+	if err != nil {
+		return accounts.Account{}, err
+	}
+	return ks.importKey(key, newPassphrase)
+}
+
+// ImportECDSA stores the given key into the key directory, encrypting it with the passphrase.
+func (ks *KeyStore) ImportECDSA(priv *ecdsa.PrivateKey, passphrase string) (accounts.Account, error) {
+	key := newKeyFromECDSA(priv)
+	if ks.cache.hasAddress(key.Address) {
+		return accounts.Account{}, fmt.Errorf("account already exists")
+	}
+	return ks.importKey(key, passphrase)
+}
+
+func (ks *KeyStore) importKey(key *Key, passphrase string) (accounts.Account, error) {
+	a := accounts.Account{Address: key.Address, URL: accounts.URL{Scheme: KeyStoreScheme, Path: ks.storage.JoinPath(keyFileName(key.Address))}}
+	if err := ks.storage.StoreKey(a.URL.Path, key, passphrase); err != nil {
+		return accounts.Account{}, err
+	}
+	ks.cache.add(a)
+	ks.refreshWallets()
+	return a, nil
+}
+
+// Update changes the passphrase of an existing account.
+func (ks *KeyStore) Update(a accounts.Account, passphrase, newPassphrase string) error {
+	a, key, err := ks.getDecryptedKey(a, passphrase)
+	if err != nil {
+		return err
+	}
+	return ks.storage.StoreKey(a.URL.Path, key, newPassphrase)
+}
+
+// ImportPreSaleKey decrypts the given Ethereum presale wallet and stores
+// a key file in the key directory. The key file is encrypted with the same passphrase.
+func (ks *KeyStore) ImportPreSaleKey(keyJSON []byte, passphrase string) (accounts.Account, error) {
+	a, _, err := importPreSaleKey(ks.storage, keyJSON, passphrase)
+	if err != nil {
+		return a, err
+	}
+	ks.cache.add(a)
+	ks.refreshWallets()
+	return a, nil
+}
+
+// zeroKey zeroes a private key in memory.
+func zeroKey(k *ecdsa.PrivateKey) {
+	b := k.D.Bits()
+	for i := range b {
+		b[i] = 0
+	}
+}
diff --git a/accounts/keystore/passphrase.go b/accounts/keystore/passphrase.go
new file mode 100644
index 0000000..fa5a09d
--- /dev/null
+++ b/accounts/keystore/passphrase.go
@@ -0,0 +1,356 @@
+// Copyright 2014 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+/*
+
+This key store behaves as KeyStorePlain with the difference that
+the private key is encrypted and on disk uses another JSON encoding.
+
+The crypto is documented at https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition
+
+*/
+
+package keystore
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/ava-labs/coreth/accounts"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/common/math"
+	"github.com/ava-labs/go-ethereum/crypto"
+	"github.com/pborman/uuid"
+	"golang.org/x/crypto/pbkdf2"
+	"golang.org/x/crypto/scrypt"
+)
+
+const (
+	keyHeaderKDF = "scrypt"
+
+	// StandardScryptN is the N parameter of Scrypt encryption algorithm, using 256MB
+	// memory and taking approximately 1s CPU time on a modern processor.
+	StandardScryptN = 1 << 18
+
+	// StandardScryptP is the P parameter of Scrypt encryption algorithm, using 256MB
+	// memory and taking approximately 1s CPU time on a modern processor.
+	StandardScryptP = 1
+
+	// LightScryptN is the N parameter of Scrypt encryption algorithm, using 4MB
+	// memory and taking approximately 100ms CPU time on a modern processor.
+	LightScryptN = 1 << 12
+
+	// LightScryptP is the P parameter of Scrypt encryption algorithm, using 4MB
+	// memory and taking approximately 100ms CPU time on a modern processor.
+	LightScryptP = 6
+
+	scryptR     = 8
+	scryptDKLen = 32
+)
+
+type keyStorePassphrase struct {
+	keysDirPath string
+	scryptN     int
+	scryptP     int
+	// skipKeyFileVerification disables the security-feature which does
+	// reads and decrypts any newly created keyfiles. This should be 'false' in all
+	// cases except tests -- setting this to 'true' is not recommended.
+	skipKeyFileVerification bool
+}
+
+func (ks keyStorePassphrase) GetKey(addr common.Address, filename, auth string) (*Key, error) {
+	// Load the key from the keystore and decrypt its contents
+	keyjson, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	key, err := DecryptKey(keyjson, auth)
+	if err != nil {
+		return nil, err
+	}
+	// Make sure we're really operating on the requested key (no swap attacks)
+	if key.Address != addr {
+		return nil, fmt.Errorf("key content mismatch: have account %x, want %x", key.Address, addr)
+	}
+	return key, nil
+}
+
+// StoreKey generates a key, encrypts with 'auth' and stores in the given directory
+func StoreKey(dir, auth string, scryptN, scryptP int) (accounts.Account, error) {
+	_, a, err := storeNewKey(&keyStorePassphrase{dir, scryptN, scryptP, false}, rand.Reader, auth)
+	return a, err
+}
+
+func (ks keyStorePassphrase) StoreKey(filename string, key *Key, auth string) error {
+	keyjson, err := EncryptKey(key, auth, ks.scryptN, ks.scryptP)
+	if err != nil {
+		return err
+	}
+	// Write into temporary file
+	tmpName, err := writeTemporaryKeyFile(filename, keyjson)
+	if err != nil {
+		return err
+	}
+	if !ks.skipKeyFileVerification {
+		// Verify that we can decrypt the file with the given password.
+		_, err = ks.GetKey(key.Address, tmpName, auth)
+		if err != nil {
+			msg := "An error was encountered when saving and verifying the keystore file. \n" +
+				"This indicates that the keystore is corrupted. \n" +
+				"The corrupted file is stored at \n%v\n" +
+				"Please file a ticket at:\n\n" +
+				"https://github.com/ethereum/go-ethereum/issues." +
+				"The error was : %s"
+			return fmt.Errorf(msg, tmpName, err)
+		}
+	}
+	return os.Rename(tmpName, filename)
+}
+
+func (ks keyStorePassphrase) JoinPath(filename string) string {
+	if filepath.IsAbs(filename) {
+		return filename
+	}
+	return filepath.Join(ks.keysDirPath, filename)
+}
+
+// Encryptdata encrypts the data given as 'data' with the password 'auth'.
+func EncryptDataV3(data, auth []byte, scryptN, scryptP int) (CryptoJSON, error) {
+
+	salt := make([]byte, 32)
+	if _, err := io.ReadFull(rand.Reader, salt); err != nil {
+		panic("reading from crypto/rand failed: " + err.Error())
+	}
+	derivedKey, err := scrypt.Key(auth, salt, scryptN, scryptR, scryptP, scryptDKLen)
+	if err != nil {
+		return CryptoJSON{}, err
+	}
+	encryptKey := derivedKey[:16]
+
+	iv := make([]byte, aes.BlockSize) // 16
+	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
+		panic("reading from crypto/rand failed: " + err.Error())
+	}
+	cipherText, err := aesCTRXOR(encryptKey, data, iv)
+	if err != nil {
+		return CryptoJSON{}, err
+	}
+	mac := crypto.Keccak256(derivedKey[16:32], cipherText)
+
+	scryptParamsJSON := make(map[string]interface{}, 5)
+	scryptParamsJSON["n"] = scryptN
+	scryptParamsJSON["r"] = scryptR
+	scryptParamsJSON["p"] = scryptP
+	scryptParamsJSON["dklen"] = scryptDKLen
+	scryptParamsJSON["salt"] = hex.EncodeToString(salt)
+	cipherParamsJSON := cipherparamsJSON{
+		IV: hex.EncodeToString(iv),
+	}
+
+	cryptoStruct := CryptoJSON{
+		Cipher:       "aes-128-ctr",
+		CipherText:   hex.EncodeToString(cipherText),
+		CipherParams: cipherParamsJSON,
+		KDF:          keyHeaderKDF,
+		KDFParams:    scryptParamsJSON,
+		MAC:          hex.EncodeToString(mac),
+	}
+	return cryptoStruct, nil
+}
+
+// EncryptKey encrypts a key using the specified scrypt parameters into a json
+// blob that can be decrypted later on.
+func EncryptKey(key *Key, auth string, scryptN, scryptP int) ([]byte, error) {
+	keyBytes := math.PaddedBigBytes(key.PrivateKey.D, 32)
+	cryptoStruct, err := EncryptDataV3(keyBytes, []byte(auth), scryptN, scryptP)
+	if err != nil {
+		return nil, err
+	}
+	encryptedKeyJSONV3 := encryptedKeyJSONV3{
+		hex.EncodeToString(key.Address[:]),
+		cryptoStruct,
+		key.Id.String(),
+		version,
+	}
+	return json.Marshal(encryptedKeyJSONV3)
+}
+
+// DecryptKey decrypts a key from a json blob, returning the private key itself.
+func DecryptKey(keyjson []byte, auth string) (*Key, error) {
+	// Parse the json into a simple map to fetch the key version
+	m := make(map[string]interface{})
+	if err := json.Unmarshal(keyjson, &m); err != nil {
+		return nil, err
+	}
+	// Depending on the version try to parse one way or another
+	var (
+		keyBytes, keyId []byte
+		err             error
+	)
+	if version, ok := m["version"].(string); ok && version == "1" {
+		k := new(encryptedKeyJSONV1)
+		if err := json.Unmarshal(keyjson, k); err != nil {
+			return nil, err
+		}
+		keyBytes, keyId, err = decryptKeyV1(k, auth)
+	} else {
+		k := new(encryptedKeyJSONV3)
+		if err := json.Unmarshal(keyjson, k); err != nil {
+			return nil, err
+		}
+		keyBytes, keyId, err = decryptKeyV3(k, auth)
+	}
+	// Handle any decryption errors and return the key
+	if err != nil {
+		return nil, err
+	}
+	key := crypto.ToECDSAUnsafe(keyBytes)
+
+	return &Key{
+		Id:         uuid.UUID(keyId),
+		Address:    crypto.PubkeyToAddress(key.PublicKey),
+		PrivateKey: key,
+	}, nil
+}
+
+func DecryptDataV3(cryptoJson CryptoJSON, auth string) ([]byte, error) {
+	if cryptoJson.Cipher != "aes-128-ctr" {
+		return nil, fmt.Errorf("Cipher not supported: %v", cryptoJson.Cipher)
+	}
+	mac, err := hex.DecodeString(cryptoJson.MAC)
+	if err != nil {
+		return nil, err
+	}
+
+	iv, err := hex.DecodeString(cryptoJson.CipherParams.IV)
+	if err != nil {
+		return nil, err
+	}
+
+	cipherText, err := hex.DecodeString(cryptoJson.CipherText)
+	if err != nil {
+		return nil, err
+	}
+
+	derivedKey, err := getKDFKey(cryptoJson, auth)
+	if err != nil {
+		return nil, err
+	}
+
+	calculatedMAC := crypto.Keccak256(derivedKey[16:32], cipherText)
+	if !bytes.Equal(calculatedMAC, mac) {
+		return nil, ErrDecrypt
+	}
+
+	plainText, err := aesCTRXOR(derivedKey[:16], cipherText, iv)
+	if err != nil {
+		return nil, err
+	}
+	return plainText, err
+}
+
+func decryptKeyV3(keyProtected *encryptedKeyJSONV3, auth string) (keyBytes []byte, keyId []byte, err error) {
+	if keyProtected.Version != version {
+		return nil, nil, fmt.Errorf("Version not supported: %v", keyProtected.Version)
+	}
+	keyId = uuid.Parse(keyProtected.Id)
+	plainText, err := DecryptDataV3(keyProtected.Crypto, auth)
+	if err != nil {
+		return nil, nil, err
+	}
+	return plainText, keyId, err
+}
+
+func decryptKeyV1(keyProtected *encryptedKeyJSONV1, auth string) (keyBytes []byte, keyId []byte, err error) {
+	keyId = uuid.Parse(keyProtected.Id)
+	mac, err := hex.DecodeString(keyProtected.Crypto.MAC)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	iv, err := hex.DecodeString(keyProtected.Crypto.CipherParams.IV)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	cipherText, err := hex.DecodeString(keyProtected.Crypto.CipherText)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	derivedKey, err := getKDFKey(keyProtected.Crypto, auth)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	calculatedMAC := crypto.Keccak256(derivedKey[16:32], cipherText)
+	if !bytes.Equal(calculatedMAC, mac) {
+		return nil, nil, ErrDecrypt
+	}
+
+	plainText, err := aesCBCDecrypt(crypto.Keccak256(derivedKey[:16])[:16], cipherText, iv)
+	if err != nil {
+		return nil, nil, err
+	}
+	return plainText, keyId, err
+}
+
+func getKDFKey(cryptoJSON CryptoJSON, auth string) ([]byte, error) {
+	authArray := []byte(auth)
+	salt, err := hex.DecodeString(cryptoJSON.KDFParams["salt"].(string))
+	if err != nil {
+		return nil, err
+	}
+	dkLen := ensureInt(cryptoJSON.KDFParams["dklen"])
+
+	if cryptoJSON.KDF == keyHeaderKDF {
+		n := ensureInt(cryptoJSON.KDFParams["n"])
+		r := ensureInt(cryptoJSON.KDFParams["r"])
+		p := ensureInt(cryptoJSON.KDFParams["p"])
+		return scrypt.Key(authArray, salt, n, r, p, dkLen)
+
+	} else if cryptoJSON.KDF == "pbkdf2" {
+		c := ensureInt(cryptoJSON.KDFParams["c"])
+		prf := cryptoJSON.KDFParams["prf"].(string)
+		if prf != "hmac-sha256" {
+			return nil, fmt.Errorf("Unsupported PBKDF2 PRF: %s", prf)
+		}
+		key := pbkdf2.Key(authArray, salt, c, dkLen, sha256.New)
+		return key, nil
+	}
+
+	return nil, fmt.Errorf("Unsupported KDF: %s", cryptoJSON.KDF)
+}
+
+// TODO: can we do without this when unmarshalling dynamic JSON?
+// why do integers in KDF params end up as float64 and not int after
+// unmarshal?
+func ensureInt(x interface{}) int {
+	res, ok := x.(int)
+	if !ok {
+		res = int(x.(float64))
+	}
+	return res
+}
diff --git a/accounts/keystore/plain.go b/accounts/keystore/plain.go
new file mode 100644
index 0000000..bc5b377
--- /dev/null
+++ b/accounts/keystore/plain.go
@@ -0,0 +1,61 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/ava-labs/go-ethereum/common"
+)
+
+type keyStorePlain struct {
+	keysDirPath string
+}
+
+func (ks keyStorePlain) GetKey(addr common.Address, filename, auth string) (*Key, error) {
+	fd, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer fd.Close()
+	key := new(Key)
+	if err := json.NewDecoder(fd).Decode(key); err != nil {
+		return nil, err
+	}
+	if key.Address != addr {
+		return nil, fmt.Errorf("key content mismatch: have address %x, want %x", key.Address, addr)
+	}
+	return key, nil
+}
+
+func (ks keyStorePlain) StoreKey(filename string, key *Key, auth string) error {
+	content, err := json.Marshal(key)
+	if err != nil {
+		return err
+	}
+	return writeKeyFile(filename, content)
+}
+
+func (ks keyStorePlain) JoinPath(filename string) string {
+	if filepath.IsAbs(filename) {
+		return filename
+	}
+	return filepath.Join(ks.keysDirPath, filename)
+}
diff --git a/accounts/keystore/presale.go b/accounts/keystore/presale.go
new file mode 100644
index 0000000..5122b0d
--- /dev/null
+++ b/accounts/keystore/presale.go
@@ -0,0 +1,147 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+
+	"github.com/ava-labs/coreth/accounts"
+	"github.com/ava-labs/go-ethereum/crypto"
+	"github.com/pborman/uuid"
+	"golang.org/x/crypto/pbkdf2"
+)
+
+// creates a Key and stores that in the given KeyStore by decrypting a presale key JSON
+func importPreSaleKey(keyStore keyStore, keyJSON []byte, password string) (accounts.Account, *Key, error) {
+	key, err := decryptPreSaleKey(keyJSON, password)
+	if err != nil {
+		return accounts.Account{}, nil, err
+	}
+	key.Id = uuid.NewRandom()
+	a := accounts.Account{
+		Address: key.Address,
+		URL: accounts.URL{
+			Scheme: KeyStoreScheme,
+			Path:   keyStore.JoinPath(keyFileName(key.Address)),
+		},
+	}
+	err = keyStore.StoreKey(a.URL.Path, key, password)
+	return a, key, err
+}
+
+func decryptPreSaleKey(fileContent []byte, password string) (key *Key, err error) {
+	preSaleKeyStruct := struct {
+		EncSeed string
+		EthAddr string
+		Email   string
+		BtcAddr string
+	}{}
+	err = json.Unmarshal(fileContent, &preSaleKeyStruct)
+	if err != nil {
+		return nil, err
+	}
+	encSeedBytes, err := hex.DecodeString(preSaleKeyStruct.EncSeed)
+	if err != nil {
+		return nil, errors.New("invalid hex in encSeed")
+	}
+	if len(encSeedBytes) < 16 {
+		return nil, errors.New("invalid encSeed, too short")
+	}
+	iv := encSeedBytes[:16]
+	cipherText := encSeedBytes[16:]
+	/*
+		See https://github.com/ethereum/pyethsaletool
+
+		pyethsaletool generates the encryption key from password by
+		2000 rounds of PBKDF2 with HMAC-SHA-256 using password as salt (:().
+		16 byte key length within PBKDF2 and resulting key is used as AES key
+	*/
+	passBytes := []byte(password)
+	derivedKey := pbkdf2.Key(passBytes, passBytes, 2000, 16, sha256.New)
+	plainText, err := aesCBCDecrypt(derivedKey, cipherText, iv)
+	if err != nil {
+		return nil, err
+	}
+	ethPriv := crypto.Keccak256(plainText)
+	ecKey := crypto.ToECDSAUnsafe(ethPriv)
+
+	key = &Key{
+		Id:         nil,
+		Address:    crypto.PubkeyToAddress(ecKey.PublicKey),
+		PrivateKey: ecKey,
+	}
+	derivedAddr := hex.EncodeToString(key.Address.Bytes()) // needed because .Hex() gives leading "0x"
+	expectedAddr := preSaleKeyStruct.EthAddr
+	if derivedAddr != expectedAddr {
+		err = fmt.Errorf("decrypted addr '%s' not equal to expected addr '%s'", derivedAddr, expectedAddr)
+	}
+	return key, err
+}
+
+func aesCTRXOR(key, inText, iv []byte) ([]byte, error) {
+	// AES-128 is selected due to size of encryptKey.
+	aesBlock, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	stream := cipher.NewCTR(aesBlock, iv)
+	outText := make([]byte, len(inText))
+	stream.XORKeyStream(outText, inText)
+	return outText, err
+}
+
+func aesCBCDecrypt(key, cipherText, iv []byte) ([]byte, error) {
+	aesBlock, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	decrypter := cipher.NewCBCDecrypter(aesBlock, iv)
+	paddedPlaintext := make([]byte, len(cipherText))
+	decrypter.CryptBlocks(paddedPlaintext, cipherText)
+	plaintext := pkcs7Unpad(paddedPlaintext)
+	if plaintext == nil {
+		return nil, ErrDecrypt
+	}
+	return plaintext, err
+}
+
+// From https://leanpub.com/gocrypto/read#leanpub-auto-block-cipher-modes
+func pkcs7Unpad(in []byte) []byte {
+	if len(in) == 0 {
+		return nil
+	}
+
+	padding := in[len(in)-1]
+	if int(padding) > len(in) || padding > aes.BlockSize {
+		return nil
+	} else if padding == 0 {
+		return nil
+	}
+
+	for i := len(in) - 1; i > len(in)-int(padding)-1; i-- {
+		if in[i] != padding {
+			return nil
+		}
+	}
+	return in[:len(in)-int(padding)]
+}
diff --git a/accounts/keystore/testdata/dupes/1 b/accounts/keystore/testdata/dupes/1
new file mode 100644
index 0000000..a3868ec
--- /dev/null
+++ b/accounts/keystore/testdata/dupes/1
@@ -0,0 +1 @@
+{"address":"f466859ead1932d743d622cb74fc058882e8648a","crypto":{"cipher":"aes-128-ctr","ciphertext":"cb664472deacb41a2e995fa7f96fe29ce744471deb8d146a0e43c7898c9ddd4d","cipherparams":{"iv":"dfd9ee70812add5f4b8f89d0811c9158"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"0d6769bf016d45c479213990d6a08d938469c4adad8a02ce507b4a4e7b7739f1"},"mac":"bac9af994b15a45dd39669fc66f9aa8a3b9dd8c22cb16e4d8d7ea089d0f1a1a9"},"id":"472e8b3d-afb6-45b5-8111-72c89895099a","version":3}
\ No newline at end of file
diff --git a/accounts/keystore/testdata/dupes/2 b/accounts/keystore/testdata/dupes/2
new file mode 100644
index 0000000..a3868ec
--- /dev/null
+++ b/accounts/keystore/testdata/dupes/2
@@ -0,0 +1 @@
+{"address":"f466859ead1932d743d622cb74fc058882e8648a","crypto":{"cipher":"aes-128-ctr","ciphertext":"cb664472deacb41a2e995fa7f96fe29ce744471deb8d146a0e43c7898c9ddd4d","cipherparams":{"iv":"dfd9ee70812add5f4b8f89d0811c9158"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"0d6769bf016d45c479213990d6a08d938469c4adad8a02ce507b4a4e7b7739f1"},"mac":"bac9af994b15a45dd39669fc66f9aa8a3b9dd8c22cb16e4d8d7ea089d0f1a1a9"},"id":"472e8b3d-afb6-45b5-8111-72c89895099a","version":3}
\ No newline at end of file
diff --git a/accounts/keystore/testdata/dupes/foo b/accounts/keystore/testdata/dupes/foo
new file mode 100644
index 0000000..c57060a
--- /dev/null
+++ b/accounts/keystore/testdata/dupes/foo
@@ -0,0 +1 @@
+{"address":"7ef5a6135f1fd6a02593eedc869c6d41d934aef8","crypto":{"cipher":"aes-128-ctr","ciphertext":"1d0839166e7a15b9c1333fc865d69858b22df26815ccf601b28219b6192974e1","cipherparams":{"iv":"8df6caa7ff1b00c4e871f002cb7921ed"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"e5e6ef3f4ea695f496b643ebd3f75c0aa58ef4070e90c80c5d3fb0241bf1595c"},"mac":"6d16dfde774845e4585357f24bce530528bc69f4f84e1e22880d34fa45c273e5"},"id":"950077c7-71e3-4c44-a4a1-143919141ed4","version":3}
\ No newline at end of file
diff --git a/accounts/keystore/testdata/keystore/.hiddenfile b/accounts/keystore/testdata/keystore/.hiddenfile
new file mode 100644
index 0000000..d91facc
--- /dev/null
+++ b/accounts/keystore/testdata/keystore/.hiddenfile
@@ -0,0 +1 @@
+{"address":"f466859ead1932d743d622cb74fc058882e8648a","crypto":{"cipher":"aes-128-ctr","ciphertext":"cb664472deacb41a2e995fa7f96fe29ce744471deb8d146a0e43c7898c9ddd4d","cipherparams":{"iv":"dfd9ee70812add5f4b8f89d0811c9158"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"0d6769bf016d45c479213990d6a08d938469c4adad8a02ce507b4a4e7b7739f1"},"mac":"bac9af994b15a45dd39669fc66f9aa8a3b9dd8c22cb16e4d8d7ea089d0f1a1a9"},"id":"472e8b3d-afb6-45b5-8111-72c89895099a","version":3}
diff --git a/accounts/keystore/testdata/keystore/README b/accounts/keystore/testdata/keystore/README
new file mode 100644
index 0000000..6af9ac3
--- /dev/null
+++ b/accounts/keystore/testdata/keystore/README
@@ -0,0 +1,21 @@
+This directory contains accounts for testing.
+The password that unlocks them is "foobar".
+
+The "good" key files which are supposed to be loadable are:
+
+- File: UTC--2016-03-22T12-57-55.920751759Z--7ef5a6135f1fd6a02593eedc869c6d41d934aef8
+  Address: 0x7ef5a6135f1fd6a02593eedc869c6d41d934aef8
+- File: aaa
+  Address: 0xf466859ead1932d743d622cb74fc058882e8648a
+- File: zzz
+  Address: 0x289d485d9771714cce91d3393d764e1311907acc
+
+The other files (including this README) are broken in various ways
+and should not be picked up by package accounts:
+
+- File: no-address (missing address field, otherwise same as "aaa")
+- File: garbage (file with random data)
+- File: empty (file with no content)
+- File: swapfile~ (should be skipped)
+- File: .hiddenfile (should be skipped)
+- File: foo/... (should be skipped because it is a directory)
diff --git a/accounts/keystore/testdata/keystore/UTC--2016-03-22T12-57-55.920751759Z--7ef5a6135f1fd6a02593eedc869c6d41d934aef8 b/accounts/keystore/testdata/keystore/UTC--2016-03-22T12-57-55.920751759Z--7ef5a6135f1fd6a02593eedc869c6d41d934aef8
new file mode 100644
index 0000000..c57060a
--- /dev/null
+++ b/accounts/keystore/testdata/keystore/UTC--2016-03-22T12-57-55.920751759Z--7ef5a6135f1fd6a02593eedc869c6d41d934aef8
@@ -0,0 +1 @@
+{"address":"7ef5a6135f1fd6a02593eedc869c6d41d934aef8","crypto":{"cipher":"aes-128-ctr","ciphertext":"1d0839166e7a15b9c1333fc865d69858b22df26815ccf601b28219b6192974e1","cipherparams":{"iv":"8df6caa7ff1b00c4e871f002cb7921ed"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"e5e6ef3f4ea695f496b643ebd3f75c0aa58ef4070e90c80c5d3fb0241bf1595c"},"mac":"6d16dfde774845e4585357f24bce530528bc69f4f84e1e22880d34fa45c273e5"},"id":"950077c7-71e3-4c44-a4a1-143919141ed4","version":3}
\ No newline at end of file
diff --git a/accounts/keystore/testdata/keystore/aaa b/accounts/keystore/testdata/keystore/aaa
new file mode 100644
index 0000000..a3868ec
--- /dev/null
+++ b/accounts/keystore/testdata/keystore/aaa
@@ -0,0 +1 @@
+{"address":"f466859ead1932d743d622cb74fc058882e8648a","crypto":{"cipher":"aes-128-ctr","ciphertext":"cb664472deacb41a2e995fa7f96fe29ce744471deb8d146a0e43c7898c9ddd4d","cipherparams":{"iv":"dfd9ee70812add5f4b8f89d0811c9158"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"0d6769bf016d45c479213990d6a08d938469c4adad8a02ce507b4a4e7b7739f1"},"mac":"bac9af994b15a45dd39669fc66f9aa8a3b9dd8c22cb16e4d8d7ea089d0f1a1a9"},"id":"472e8b3d-afb6-45b5-8111-72c89895099a","version":3}
\ No newline at end of file
diff --git a/accounts/keystore/testdata/keystore/empty b/accounts/keystore/testdata/keystore/empty
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/accounts/keystore/testdata/keystore/empty
diff --git a/accounts/keystore/testdata/keystore/foo/fd9bd350f08ee3c0c19b85a8e16114a11a60aa4e b/accounts/keystore/testdata/keystore/foo/fd9bd350f08ee3c0c19b85a8e16114a11a60aa4e
new file mode 100644
index 0000000..309841e
--- /dev/null
+++ b/accounts/keystore/testdata/keystore/foo/fd9bd350f08ee3c0c19b85a8e16114a11a60aa4e
@@ -0,0 +1 @@
+{"address":"fd9bd350f08ee3c0c19b85a8e16114a11a60aa4e","crypto":{"cipher":"aes-128-ctr","ciphertext":"8124d5134aa4a927c79fd852989e4b5419397566f04b0936a1eb1d168c7c68a5","cipherparams":{"iv":"e2febe17176414dd2cda28287947eb2f"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":4096,"p":6,"r":8,"salt":"44b415ede89f3bdd6830390a21b78965f571b347a589d1d943029f016c5e8bd5"},"mac":"5e149ff25bfd9dd45746a84bb2bcd2f015f2cbca2b6d25c5de8c29617f71fe5b"},"id":"d6ac5452-2b2c-4d3c-ad80-4bf0327d971c","version":3}
\ No newline at end of file
diff --git a/accounts/keystore/testdata/keystore/garbage b/accounts/keystore/testdata/keystore/garbage
new file mode 100644
index 0000000..ff45091
--- /dev/null
+++ b/accounts/keystore/testdata/keystore/garbage
diff --git a/accounts/keystore/testdata/keystore/no-address b/accounts/keystore/testdata/keystore/no-address
new file mode 100644
index 0000000..ad51269
--- /dev/null
+++ b/accounts/keystore/testdata/keystore/no-address
@@ -0,0 +1 @@
+{"crypto":{"cipher":"aes-128-ctr","ciphertext":"cb664472deacb41a2e995fa7f96fe29ce744471deb8d146a0e43c7898c9ddd4d","cipherparams":{"iv":"dfd9ee70812add5f4b8f89d0811c9158"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"0d6769bf016d45c479213990d6a08d938469c4adad8a02ce507b4a4e7b7739f1"},"mac":"bac9af994b15a45dd39669fc66f9aa8a3b9dd8c22cb16e4d8d7ea089d0f1a1a9"},"id":"472e8b3d-afb6-45b5-8111-72c89895099a","version":3}
\ No newline at end of file
diff --git a/accounts/keystore/testdata/keystore/zero b/accounts/keystore/testdata/keystore/zero
new file mode 100644
index 0000000..b52617f
--- /dev/null
+++ b/accounts/keystore/testdata/keystore/zero
@@ -0,0 +1 @@
+{"address":"0000000000000000000000000000000000000000","crypto":{"cipher":"aes-128-ctr","ciphertext":"cb664472deacb41a2e995fa7f96fe29ce744471deb8d146a0e43c7898c9ddd4d","cipherparams":{"iv":"dfd9ee70812add5f4b8f89d0811c9158"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"0d6769bf016d45c479213990d6a08d938469c4adad8a02ce507b4a4e7b7739f1"},"mac":"bac9af994b15a45dd39669fc66f9aa8a3b9dd8c22cb16e4d8d7ea089d0f1a1a9"},"id":"472e8b3d-afb6-45b5-8111-72c89895099a","version":3}
\ No newline at end of file
diff --git a/accounts/keystore/testdata/keystore/zzz b/accounts/keystore/testdata/keystore/zzz
new file mode 100644
index 0000000..cfd8a47
--- /dev/null
+++ b/accounts/keystore/testdata/keystore/zzz
@@ -0,0 +1 @@
+{"address":"289d485d9771714cce91d3393d764e1311907acc","crypto":{"cipher":"aes-128-ctr","ciphertext":"faf32ca89d286b107f5e6d842802e05263c49b78d46eac74e6109e9a963378ab","cipherparams":{"iv":"558833eec4a665a8c55608d7d503407d"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"d571fff447ffb24314f9513f5160246f09997b857ac71348b73e785aab40dc04"},"mac":"21edb85ff7d0dab1767b9bf498f2c3cb7be7609490756bd32300bb213b59effe"},"id":"3279afcf-55ba-43ff-8997-02dcc46a6525","version":3}
\ No newline at end of file
diff --git a/accounts/keystore/testdata/v1/cb61d5a9c4896fb9658090b597ef0e7be6f7b67e/cb61d5a9c4896fb9658090b597ef0e7be6f7b67e b/accounts/keystore/testdata/v1/cb61d5a9c4896fb9658090b597ef0e7be6f7b67e/cb61d5a9c4896fb9658090b597ef0e7be6f7b67e
new file mode 100644
index 0000000..498d813
--- /dev/null
+++ b/accounts/keystore/testdata/v1/cb61d5a9c4896fb9658090b597ef0e7be6f7b67e/cb61d5a9c4896fb9658090b597ef0e7be6f7b67e
@@ -0,0 +1 @@
+{"address":"cb61d5a9c4896fb9658090b597ef0e7be6f7b67e","Crypto":{"cipher":"aes-128-cbc","ciphertext":"6143d3192db8b66eabd693d9c4e414dcfaee52abda451af79ccf474dafb35f1bfc7ea013aa9d2ee35969a1a2e8d752d0","cipherparams":{"iv":"35337770fc2117994ecdcad026bccff4"},"kdf":"scrypt","kdfparams":{"n":262144,"r":8,"p":1,"dklen":32,"salt":"9afcddebca541253a2f4053391c673ff9fe23097cd8555d149d929e4ccf1257f"},"mac":"3f3d5af884b17a100b0b3232c0636c230a54dc2ac8d986227219b0dd89197644","version":"1"},"id":"e25f7c1f-d318-4f29-b62c-687190d4d299","version":"1"}
\ No newline at end of file
diff --git a/accounts/keystore/testdata/v1_test_vector.json b/accounts/keystore/testdata/v1_test_vector.json
new file mode 100644
index 0000000..3d09b55
--- /dev/null
+++ b/accounts/keystore/testdata/v1_test_vector.json
@@ -0,0 +1,28 @@
+{
+    "test1": {
+        "json": {
+            "Crypto": {
+                "cipher": "aes-128-cbc",
+                "cipherparams": {
+                    "iv": "35337770fc2117994ecdcad026bccff4"
+                },
+                "ciphertext": "6143d3192db8b66eabd693d9c4e414dcfaee52abda451af79ccf474dafb35f1bfc7ea013aa9d2ee35969a1a2e8d752d0",
+                "kdf": "scrypt",
+                "kdfparams": {
+                    "dklen": 32,
+                    "n": 262144,
+                    "p": 1,
+                    "r": 8,
+                    "salt": "9afcddebca541253a2f4053391c673ff9fe23097cd8555d149d929e4ccf1257f"
+                },
+                "mac": "3f3d5af884b17a100b0b3232c0636c230a54dc2ac8d986227219b0dd89197644",
+                "version": "1"
+            },
+            "address": "cb61d5a9c4896fb9658090b597ef0e7be6f7b67e",
+            "id": "e25f7c1f-d318-4f29-b62c-687190d4d299",
+            "version": "1"
+        },
+        "password": "g",
+        "priv": "d1b1178d3529626a1a93e073f65028370d14c7eb0936eb42abef05db6f37ad7d"
+    }
+}
diff --git a/accounts/keystore/testdata/v3_test_vector.json b/accounts/keystore/testdata/v3_test_vector.json
new file mode 100644
index 0000000..1e7f790
--- /dev/null
+++ b/accounts/keystore/testdata/v3_test_vector.json
@@ -0,0 +1,97 @@
+{
+    "wikipage_test_vector_scrypt": {
+        "json": {
+            "crypto" : {
+                "cipher" : "aes-128-ctr",
+                "cipherparams" : {
+                    "iv" : "83dbcc02d8ccb40e466191a123791e0e"
+                },
+                "ciphertext" : "d172bf743a674da9cdad04534d56926ef8358534d458fffccd4e6ad2fbde479c",
+                "kdf" : "scrypt",
+                "kdfparams" : {
+                    "dklen" : 32,
+                    "n" : 262144,
+                    "r" : 1,
+                    "p" : 8,
+                    "salt" : "ab0c7876052600dd703518d6fc3fe8984592145b591fc8fb5c6d43190334ba19"
+                },
+                "mac" : "2103ac29920d71da29f15d75b4a16dbe95cfd7ff8faea1056c33131d846e3097"
+            },
+            "id" : "3198bc9c-6672-5ab3-d995-4942343ae5b6",
+            "version" : 3
+        },
+        "password": "testpassword",
+        "priv": "7a28b5ba57c53603b0b07b56bba752f7784bf506fa95edc395f5cf6c7514fe9d"
+    },
+    "wikipage_test_vector_pbkdf2": {
+        "json": {
+            "crypto" : {
+                "cipher" : "aes-128-ctr",
+                "cipherparams" : {
+                    "iv" : "6087dab2f9fdbbfaddc31a909735c1e6"
+                },
+                "ciphertext" : "5318b4d5bcd28de64ee5559e671353e16f075ecae9f99c7a79a38af5f869aa46",
+                "kdf" : "pbkdf2",
+                "kdfparams" : {
+                    "c" : 262144,
+                    "dklen" : 32,
+                    "prf" : "hmac-sha256",
+                    "salt" : "ae3cd4e7013836a3df6bd7241b12db061dbe2c6785853cce422d148a624ce0bd"
+                },
+                "mac" : "517ead924a9d0dc3124507e3393d175ce3ff7c1e96529c6c555ce9e51205e9b2"
+            },
+            "id" : "3198bc9c-6672-5ab3-d995-4942343ae5b6",
+            "version" : 3
+        },
+        "password": "testpassword",
+        "priv": "7a28b5ba57c53603b0b07b56bba752f7784bf506fa95edc395f5cf6c7514fe9d"
+    },
+    "31_byte_key": {
+        "json": {
+            "crypto" : {
+                "cipher" : "aes-128-ctr",
+                "cipherparams" : {
+                    "iv" : "e0c41130a323adc1446fc82f724bca2f"
+                },
+                "ciphertext" : "9517cd5bdbe69076f9bf5057248c6c050141e970efa36ce53692d5d59a3984",
+                "kdf" : "scrypt",
+                "kdfparams" : {
+                    "dklen" : 32,
+                    "n" : 2,
+                    "r" : 8,
+                    "p" : 1,
+                    "salt" : "711f816911c92d649fb4c84b047915679933555030b3552c1212609b38208c63"
+                },
+                "mac" : "d5e116151c6aa71470e67a7d42c9620c75c4d23229847dcc127794f0732b0db5"
+            },
+            "id" : "fecfc4ce-e956-48fd-953b-30f8b52ed66c",
+            "version" : 3
+        },
+        "password": "foo",
+        "priv": "fa7b3db73dc7dfdf8c5fbdb796d741e4488628c41fc4febd9160a866ba0f35"
+    },
+    "30_byte_key": {
+        "json": {
+            "crypto" : {
+                "cipher" : "aes-128-ctr",
+                "cipherparams" : {
+                    "iv" : "3ca92af36ad7c2cd92454c59cea5ef00"
+                },
+                "ciphertext" : "108b7d34f3442fc26ab1ab90ca91476ba6bfa8c00975a49ef9051dc675aa",
+                "kdf" : "scrypt",
+                "kdfparams" : {
+                    "dklen" : 32,
+                    "n" : 2,
+                    "r" : 8,
+                    "p" : 1,
+                    "salt" : "d0769e608fb86cda848065642a9c6fa046845c928175662b8e356c77f914cd3b"
+                },
+                "mac" : "75d0e6759f7b3cefa319c3be41680ab6beea7d8328653474bd06706d4cc67420"
+            },
+            "id" : "a37e1559-5955-450d-8075-7b8931b392b2",
+            "version" : 3
+        },
+        "password": "foo",
+        "priv": "81c29e8142bb6a81bef5a92bda7a8328a5c85bb2f9542e76f9b0f94fc018"
+    }
+}
diff --git a/accounts/keystore/testdata/very-light-scrypt.json b/accounts/keystore/testdata/very-light-scrypt.json
new file mode 100644
index 0000000..d23b9b2
--- /dev/null
+++ b/accounts/keystore/testdata/very-light-scrypt.json
@@ -0,0 +1 @@
+{"address":"45dea0fb0bba44f4fcf290bba71fd57d7117cbb8","crypto":{"cipher":"aes-128-ctr","ciphertext":"b87781948a1befd247bff51ef4063f716cf6c2d3481163e9a8f42e1f9bb74145","cipherparams":{"iv":"dc4926b48a105133d2f16b96833abf1e"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":2,"p":1,"r":8,"salt":"004244bbdc51cadda545b1cfa43cff9ed2ae88e08c61f1479dbb45410722f8f0"},"mac":"39990c1684557447940d4c69e06b1b82b2aceacb43f284df65c956daf3046b85"},"id":"ce541d8d-c79b-40f8-9f8c-20f59616faba","version":3}
diff --git a/accounts/keystore/wallet.go b/accounts/keystore/wallet.go
new file mode 100644
index 0000000..3be901b
--- /dev/null
+++ b/accounts/keystore/wallet.go
@@ -0,0 +1,148 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"math/big"
+
+	"github.com/ava-labs/coreth/accounts"
+	"github.com/ava-labs/coreth/core/types"
+	ethereum "github.com/ava-labs/go-ethereum"
+	"github.com/ava-labs/go-ethereum/crypto"
+)
+
+// keystoreWallet implements the accounts.Wallet interface for the original
+// keystore.
+type keystoreWallet struct {
+	account  accounts.Account // Single account contained in this wallet
+	keystore *KeyStore        // Keystore where the account originates from
+}
+
+// URL implements accounts.Wallet, returning the URL of the account within.
+func (w *keystoreWallet) URL() accounts.URL {
+	return w.account.URL
+}
+
+// Status implements accounts.Wallet, returning whether the account held by the
+// keystore wallet is unlocked or not.
+func (w *keystoreWallet) Status() (string, error) {
+	w.keystore.mu.RLock()
+	defer w.keystore.mu.RUnlock()
+
+	if _, ok := w.keystore.unlocked[w.account.Address]; ok {
+		return "Unlocked", nil
+	}
+	return "Locked", nil
+}
+
+// Open implements accounts.Wallet, but is a noop for plain wallets since there
+// is no connection or decryption step necessary to access the list of accounts.
+func (w *keystoreWallet) Open(passphrase string) error { return nil }
+
+// Close implements accounts.Wallet, but is a noop for plain wallets since there
+// is no meaningful open operation.
+func (w *keystoreWallet) Close() error { return nil }
+
+// Accounts implements accounts.Wallet, returning an account list consisting of
+// a single account that the plain kestore wallet contains.
+func (w *keystoreWallet) Accounts() []accounts.Account {
+	return []accounts.Account{w.account}
+}
+
+// Contains implements accounts.Wallet, returning whether a particular account is
+// or is not wrapped by this wallet instance.
+func (w *keystoreWallet) Contains(account accounts.Account) bool {
+	return account.Address == w.account.Address && (account.URL == (accounts.URL{}) || account.URL == w.account.URL)
+}
+
+// Derive implements accounts.Wallet, but is a noop for plain wallets since there
+// is no notion of hierarchical account derivation for plain keystore accounts.
+func (w *keystoreWallet) Derive(path accounts.DerivationPath, pin bool) (accounts.Account, error) {
+	return accounts.Account{}, accounts.ErrNotSupported
+}
+
+// SelfDerive implements accounts.Wallet, but is a noop for plain wallets since
+// there is no notion of hierarchical account derivation for plain keystore accounts.
+func (w *keystoreWallet) SelfDerive(bases []accounts.DerivationPath, chain ethereum.ChainStateReader) {
+}
+
+// signHash attempts to sign the given hash with
+// the given account. If the wallet does not wrap this particular account, an
+// error is returned to avoid account leakage (even though in theory we may be
+// able to sign via our shared keystore backend).
+func (w *keystoreWallet) signHash(account accounts.Account, hash []byte) ([]byte, error) {
+	// Make sure the requested account is contained within
+	if !w.Contains(account) {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignHash(account, hash)
+}
+
+// SignData signs keccak256(data). The mimetype parameter describes the type of data being signed
+func (w *keystoreWallet) SignData(account accounts.Account, mimeType string, data []byte) ([]byte, error) {
+	return w.signHash(account, crypto.Keccak256(data))
+}
+
+// SignDataWithPassphrase signs keccak256(data). The mimetype parameter describes the type of data being signed
+func (w *keystoreWallet) SignDataWithPassphrase(account accounts.Account, passphrase, mimeType string, data []byte) ([]byte, error) {
+	// Make sure the requested account is contained within
+	if !w.Contains(account) {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignHashWithPassphrase(account, passphrase, crypto.Keccak256(data))
+}
+
+func (w *keystoreWallet) SignText(account accounts.Account, text []byte) ([]byte, error) {
+	return w.signHash(account, accounts.TextHash(text))
+}
+
+// SignTextWithPassphrase implements accounts.Wallet, attempting to sign the
+// given hash with the given account using passphrase as extra authentication.
+func (w *keystoreWallet) SignTextWithPassphrase(account accounts.Account, passphrase string, text []byte) ([]byte, error) {
+	// Make sure the requested account is contained within
+	if !w.Contains(account) {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignHashWithPassphrase(account, passphrase, accounts.TextHash(text))
+}
+
+// SignTx implements accounts.Wallet, attempting to sign the given transaction
+// with the given account. If the wallet does not wrap this particular account,
+// an error is returned to avoid account leakage (even though in theory we may
+// be able to sign via our shared keystore backend).
+func (w *keystoreWallet) SignTx(account accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	// Make sure the requested account is contained within
+	if !w.Contains(account) {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignTx(account, tx, chainID)
+}
+
+// SignTxWithPassphrase implements accounts.Wallet, attempting to sign the given
+// transaction with the given account using passphrase as extra authentication.
+func (w *keystoreWallet) SignTxWithPassphrase(account accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	// Make sure the requested account is contained within
+	if !w.Contains(account) {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignTxWithPassphrase(account, passphrase, tx, chainID)
+}
diff --git a/accounts/keystore/watch.go b/accounts/keystore/watch.go
new file mode 100644
index 0000000..7fa5b3c
--- /dev/null
+++ b/accounts/keystore/watch.go
@@ -0,0 +1,108 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build darwin,!ios,cgo freebsd linux,!arm64 netbsd solaris
+
+package keystore
+
+import (
+	"time"
+
+	"github.com/ava-labs/go-ethereum/log"
+	"github.com/rjeczalik/notify"
+)
+
+type watcher struct {
+	ac       *accountCache
+	starting bool
+	running  bool
+	ev       chan notify.EventInfo
+	quit     chan struct{}
+}
+
+func newWatcher(ac *accountCache) *watcher {
+	return &watcher{
+		ac:   ac,
+		ev:   make(chan notify.EventInfo, 10),
+		quit: make(chan struct{}),
+	}
+}
+
+// starts the watcher loop in the background.
+// Start a watcher in the background if that's not already in progress.
+// The caller must hold w.ac.mu.
+func (w *watcher) start() {
+	if w.starting || w.running {
+		return
+	}
+	w.starting = true
+	go w.loop()
+}
+
+func (w *watcher) close() {
+	close(w.quit)
+}
+
+func (w *watcher) loop() {
+	defer func() {
+		w.ac.mu.Lock()
+		w.running = false
+		w.starting = false
+		w.ac.mu.Unlock()
+	}()
+	logger := log.New("path", w.ac.keydir)
+
+	if err := notify.Watch(w.ac.keydir, w.ev, notify.All); err != nil {
+		logger.Trace("Failed to watch keystore folder", "err", err)
+		return
+	}
+	defer notify.Stop(w.ev)
+	logger.Trace("Started watching keystore folder")
+	defer logger.Trace("Stopped watching keystore folder")
+
+	w.ac.mu.Lock()
+	w.running = true
+	w.ac.mu.Unlock()
+
+	// Wait for file system events and reload.
+	// When an event occurs, the reload call is delayed a bit so that
+	// multiple events arriving quickly only cause a single reload.
+	var (
+		debounceDuration = 500 * time.Millisecond
+		rescanTriggered  = false
+		debounce         = time.NewTimer(0)
+	)
+	// Ignore initial trigger
+	if !debounce.Stop() {
+		<-debounce.C
+	}
+	defer debounce.Stop()
+	for {
+		select {
+		case <-w.quit:
+			return
+		case <-w.ev:
+			// Trigger the scan (with delay), if not already triggered
+			if !rescanTriggered {
+				debounce.Reset(debounceDuration)
+				rescanTriggered = true
+			}
+		case <-debounce.C:
+			w.ac.scanAccounts()
+			rescanTriggered = false
+		}
+	}
+}
diff --git a/accounts/keystore/watch_fallback.go b/accounts/keystore/watch_fallback.go
new file mode 100644
index 0000000..de0e87f
--- /dev/null
+++ b/accounts/keystore/watch_fallback.go
@@ -0,0 +1,28 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build darwin,!cgo ios linux,arm64 windows !darwin,!freebsd,!linux,!netbsd,!solaris
+
+// This is the fallback implementation of directory watching.
+// It is used on unsupported platforms.
+
+package keystore
+
+type watcher struct{ running bool }
+
+func newWatcher(*accountCache) *watcher { return new(watcher) }
+func (*watcher) start()                 {}
+func (*watcher) close()                 {}
diff --git a/accounts/manager.go b/accounts/manager.go
new file mode 100644
index 0000000..39211da
--- /dev/null
+++ b/accounts/manager.go
@@ -0,0 +1,229 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+import (
+	"reflect"
+	"sort"
+	"sync"
+
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/event"
+)
+
+// Config contains the settings of the global account manager.
+//
+// TODO(rjl493456442, karalabe, holiman): Get rid of this when account management
+// is removed in favor of Clef.
+type Config struct {
+	InsecureUnlockAllowed bool // Whether account unlocking in insecure environment is allowed
+}
+
+// Manager is an overarching account manager that can communicate with various
+// backends for signing transactions.
+type Manager struct {
+	config   *Config                    // Global account manager configurations
+	backends map[reflect.Type][]Backend // Index of backends currently registered
+	updaters []event.Subscription       // Wallet update subscriptions for all backends
+	updates  chan WalletEvent           // Subscription sink for backend wallet changes
+	wallets  []Wallet                   // Cache of all wallets from all registered backends
+
+	feed event.Feed // Wallet feed notifying of arrivals/departures
+
+	quit chan chan error
+	lock sync.RWMutex
+}
+
+// NewManager creates a generic account manager to sign transaction via various
+// supported backends.
+func NewManager(config *Config, backends ...Backend) *Manager {
+	// Retrieve the initial list of wallets from the backends and sort by URL
+	var wallets []Wallet
+	for _, backend := range backends {
+		wallets = merge(wallets, backend.Wallets()...)
+	}
+	// Subscribe to wallet notifications from all backends
+	updates := make(chan WalletEvent, 4*len(backends))
+
+	subs := make([]event.Subscription, len(backends))
+	for i, backend := range backends {
+		subs[i] = backend.Subscribe(updates)
+	}
+	// Assemble the account manager and return
+	am := &Manager{
+		config:   config,
+		backends: make(map[reflect.Type][]Backend),
+		updaters: subs,
+		updates:  updates,
+		wallets:  wallets,
+		quit:     make(chan chan error),
+	}
+	for _, backend := range backends {
+		kind := reflect.TypeOf(backend)
+		am.backends[kind] = append(am.backends[kind], backend)
+	}
+	go am.update()
+
+	return am
+}
+
+// Close terminates the account manager's internal notification processes.
+func (am *Manager) Close() error {
+	errc := make(chan error)
+	am.quit <- errc
+	return <-errc
+}
+
+// Config returns the configuration of account manager.
+func (am *Manager) Config() *Config {
+	return am.config
+}
+
+// update is the wallet event loop listening for notifications from the backends
+// and updating the cache of wallets.
+func (am *Manager) update() {
+	// Close all subscriptions when the manager terminates
+	defer func() {
+		am.lock.Lock()
+		for _, sub := range am.updaters {
+			sub.Unsubscribe()
+		}
+		am.updaters = nil
+		am.lock.Unlock()
+	}()
+
+	// Loop until termination
+	for {
+		select {
+		case event := <-am.updates:
+			// Wallet event arrived, update local cache
+			am.lock.Lock()
+			switch event.Kind {
+			case WalletArrived:
+				am.wallets = merge(am.wallets, event.Wallet)
+			case WalletDropped:
+				am.wallets = drop(am.wallets, event.Wallet)
+			}
+			am.lock.Unlock()
+
+			// Notify any listeners of the event
+			am.feed.Send(event)
+
+		case errc := <-am.quit:
+			// Manager terminating, return
+			errc <- nil
+			return
+		}
+	}
+}
+
+// Backends retrieves the backend(s) with the given type from the account manager.
+func (am *Manager) Backends(kind reflect.Type) []Backend {
+	return am.backends[kind]
+}
+
+// Wallets returns all signer accounts registered under this account manager.
+func (am *Manager) Wallets() []Wallet {
+	am.lock.RLock()
+	defer am.lock.RUnlock()
+
+	cpy := make([]Wallet, len(am.wallets))
+	copy(cpy, am.wallets)
+	return cpy
+}
+
+// Wallet retrieves the wallet associated with a particular URL.
+func (am *Manager) Wallet(url string) (Wallet, error) {
+	am.lock.RLock()
+	defer am.lock.RUnlock()
+
+	parsed, err := parseURL(url)
+	if err != nil {
+		return nil, err
+	}
+	for _, wallet := range am.Wallets() {
+		if wallet.URL() == parsed {
+			return wallet, nil
+		}
+	}
+	return nil, ErrUnknownWallet
+}
+
+// Accounts returns all account addresses of all wallets within the account manager
+func (am *Manager) Accounts() []common.Address {
+	am.lock.RLock()
+	defer am.lock.RUnlock()
+
+	addresses := make([]common.Address, 0) // return [] instead of nil if empty
+	for _, wallet := range am.wallets {
+		for _, account := range wallet.Accounts() {
+			addresses = append(addresses, account.Address)
+		}
+	}
+	return addresses
+}
+
+// Find attempts to locate the wallet corresponding to a specific account. Since
+// accounts can be dynamically added to and removed from wallets, this method has
+// a linear runtime in the number of wallets.
+func (am *Manager) Find(account Account) (Wallet, error) {
+	am.lock.RLock()
+	defer am.lock.RUnlock()
+
+	for _, wallet := range am.wallets {
+		if wallet.Contains(account) {
+			return wallet, nil
+		}
+	}
+	return nil, ErrUnknownAccount
+}
+
+// Subscribe creates an async subscription to receive notifications when the
+// manager detects the arrival or departure of a wallet from any of its backends.
+func (am *Manager) Subscribe(sink chan<- WalletEvent) event.Subscription {
+	return am.feed.Subscribe(sink)
+}
+
+// merge is a sorted analogue of append for wallets, where the ordering of the
+// origin list is preserved by inserting new wallets at the correct position.
+//
+// The original slice is assumed to be already sorted by URL.
+func merge(slice []Wallet, wallets ...Wallet) []Wallet {
+	for _, wallet := range wallets {
+		n := sort.Search(len(slice), func(i int) bool { return slice[i].URL().Cmp(wallet.URL()) >= 0 })
+		if n == len(slice) {
+			slice = append(slice, wallet)
+			continue
+		}
+		slice = append(slice[:n], append([]Wallet{wallet}, slice[n:]...)...)
+	}
+	return slice
+}
+
+// drop is the couterpart of merge, which looks up wallets from within the sorted
+// cache and removes the ones specified.
+func drop(slice []Wallet, wallets ...Wallet) []Wallet {
+	for _, wallet := range wallets {
+		n := sort.Search(len(slice), func(i int) bool { return slice[i].URL().Cmp(wallet.URL()) >= 0 })
+		if n == len(slice) {
+			// Wallet not found, may happen during startup
+			continue
+		}
+		slice = append(slice[:n], slice[n+1:]...)
+	}
+	return slice
+}
diff --git a/accounts/scwallet/README.md b/accounts/scwallet/README.md
new file mode 100644
index 0000000..cfca916
--- /dev/null
+++ b/accounts/scwallet/README.md
@@ -0,0 +1,102 @@
+# Using the smartcard wallet
+
+## Requirements
+
+  * A USB smartcard reader
+  * A keycard that supports the status app
+  * PCSCD version 4.3 running on your system **Only version 4.3 is currently supported**
+
+## Preparing the smartcard
+
+  **WARNING: FOILLOWING THESE INSTRUCTIONS WILL DESTROY THE MASTER KEY ON YOUR CARD. ONLY PROCEED IF NO FUNDS ARE ASSOCIATED WITH THESE ACCOUNTS**
+
+  You can use status' [keycard-cli](https://github.com/status-im/keycard-cli) and you should get _at least_ version 2.1.1 of their [smartcard application](https://github.com/status-im/status-keycard/releases/download/2.2.1/keycard_v2.2.1.cap)
+
+  You also need to make sure that the PCSC daemon is running on your system.
+
+  Then, you can install the application to the card by typing:
+
+  ```
+  keycard install -a keycard_v2.2.1.cap && keycard init
+  ```
+
+  At the end of this process, you will be provided with a PIN, a PUK and a pairing password. Write them down, you'll need them shortly.
+
+  Start `geth` with the `console` command. You will notice the following warning:
+
+  ```
+  WARN [04-09|16:58:38.898] Failed to open wallet                    url=keycard://044def09                          err="smartcard: pairing password needed"
+  ```
+
+  Write down the URL (`keycard://044def09` in this example). Then ask `geth` to open the wallet:
+
+  ```
+  > personal.openWallet("keycard://044def09")
+  Please enter the pairing password:
+  ```
+
+  Enter the pairing password that you have received during card initialization. Same with the PIN that you will subsequently be
+  asked for.
+  
+  If everything goes well, you should see your new account when typing `personal` on the console:
+
+  ```
+  > personal
+  WARN [04-09|17:02:07.330] Smartcard wallet account derivation failed url=keycard://044def09 err="Unexpected response status Cla=0x80, Ins=0xd1, Sw=0x6985"
+  {
+    listAccounts: [],
+    listWallets: [{
+        status: "Empty, waiting for initialization",
+        url: "keycard://044def09"
+    }],
+    ...
+  }
+  ```
+
+  So the communication with the card is working, but there is no key associated with this wallet. Let's create it:
+
+  ```
+  > personal.initializeWallet("keycard://044def09")
+  "tilt ... impact"
+  ```
+
+  You should get a list of words, this is your seed so write them down. Your wallet should now be initialized:
+
+  ```
+  > personal.listWallets
+  [{
+    accounts: [{
+        address: "0x678b7cd55c61917defb23546a41803c5bfefbc7a",
+        url: "keycard://044d/m/44'/60'/0'/0/0"
+    }],
+    status: "Online",
+    url: "keycard://044def09"
+  }]
+  ```
+
+  You're all set!
+
+## Usage
+
+  1. Start `geth` with the `console` command
+  2. Check the card's URL by checking `personal.listWallets`:
+
+```
+  listWallets: [{
+      status: "Online, can derive public keys",
+      url: "keycard://a4d73015"
+  }]
+```
+
+  3. Open the wallet, you will be prompted for your pairing password, then PIN:
+
+```
+personal.openWallet("keycard://a4d73015")
+```
+
+  4. Check that creation was successful by typing e.g. `personal`. Then use it like a regular wallet.
+
+## Known issues
+
+  * Starting geth with a valid card seems to make firefox crash.
+  * PCSC version 4.4 should work, but is currently untested
diff --git a/accounts/scwallet/apdu.go b/accounts/scwallet/apdu.go
new file mode 100644
index 0000000..bd36606
--- /dev/null
+++ b/accounts/scwallet/apdu.go
@@ -0,0 +1,87 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package scwallet
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+)
+
+// commandAPDU represents an application data unit sent to a smartcard.
+type commandAPDU struct {
+	Cla, Ins, P1, P2 uint8  // Class, Instruction, Parameter 1, Parameter 2
+	Data             []byte // Command data
+	Le               uint8  // Command data length
+}
+
+// serialize serializes a command APDU.
+func (ca commandAPDU) serialize() ([]byte, error) {
+	buf := new(bytes.Buffer)
+
+	if err := binary.Write(buf, binary.BigEndian, ca.Cla); err != nil {
+		return nil, err
+	}
+	if err := binary.Write(buf, binary.BigEndian, ca.Ins); err != nil {
+		return nil, err
+	}
+	if err := binary.Write(buf, binary.BigEndian, ca.P1); err != nil {
+		return nil, err
+	}
+	if err := binary.Write(buf, binary.BigEndian, ca.P2); err != nil {
+		return nil, err
+	}
+	if len(ca.Data) > 0 {
+		if err := binary.Write(buf, binary.BigEndian, uint8(len(ca.Data))); err != nil {
+			return nil, err
+		}
+		if err := binary.Write(buf, binary.BigEndian, ca.Data); err != nil {
+			return nil, err
+		}
+	}
+	if err := binary.Write(buf, binary.BigEndian, ca.Le); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// responseAPDU represents an application data unit received from a smart card.
+type responseAPDU struct {
+	Data     []byte // response data
+	Sw1, Sw2 uint8  // status words 1 and 2
+}
+
+// deserialize deserializes a response APDU.
+func (ra *responseAPDU) deserialize(data []byte) error {
+	if len(data) < 2 {
+		return fmt.Errorf("can not deserialize data: payload too short (%d < 2)", len(data))
+	}
+
+	ra.Data = make([]byte, len(data)-2)
+
+	buf := bytes.NewReader(data)
+	if err := binary.Read(buf, binary.BigEndian, &ra.Data); err != nil {
+		return err
+	}
+	if err := binary.Read(buf, binary.BigEndian, &ra.Sw1); err != nil {
+		return err
+	}
+	if err := binary.Read(buf, binary.BigEndian, &ra.Sw2); err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/accounts/scwallet/hub.go b/accounts/scwallet/hub.go
new file mode 100644
index 0000000..ceb422c
--- /dev/null
+++ b/accounts/scwallet/hub.go
@@ -0,0 +1,302 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// This package implements support for smartcard-based hardware wallets such as
+// the one written by Status: https://github.com/status-im/hardware-wallet
+//
+// This implementation of smartcard wallets have a different interaction process
+// to other types of hardware wallet. The process works like this:
+//
+// 1. (First use with a given client) Establish a pairing between hardware
+//    wallet and client. This requires a secret value called a 'pairing password'.
+//    You can pair with an unpaired wallet with `personal.openWallet(URI, pairing password)`.
+// 2. (First use only) Initialize the wallet, which generates a keypair, stores
+//    it on the wallet, and returns it so the user can back it up. You can
+//    initialize a wallet with `personal.initializeWallet(URI)`.
+// 3. Connect to the wallet using the pairing information established in step 1.
+//    You can connect to a paired wallet with `personal.openWallet(URI, PIN)`.
+// 4. Interact with the wallet as normal.
+
+package scwallet
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sort"
+	"sync"
+	"time"
+
+	"github.com/ava-labs/coreth/accounts"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/event"
+	"github.com/ava-labs/go-ethereum/log"
+	pcsc "github.com/gballet/go-libpcsclite"
+)
+
+// Scheme is the URI prefix for smartcard wallets.
+const Scheme = "keycard"
+
+// refreshCycle is the maximum time between wallet refreshes (if USB hotplug
+// notifications don't work).
+const refreshCycle = time.Second
+
+// refreshThrottling is the minimum time between wallet refreshes to avoid thrashing.
+const refreshThrottling = 500 * time.Millisecond
+
+// smartcardPairing contains information about a smart card we have paired with
+// or might pair with the hub.
+type smartcardPairing struct {
+	PublicKey    []byte                                     `json:"publicKey"`
+	PairingIndex uint8                                      `json:"pairingIndex"`
+	PairingKey   []byte                                     `json:"pairingKey"`
+	Accounts     map[common.Address]accounts.DerivationPath `json:"accounts"`
+}
+
+// Hub is a accounts.Backend that can find and handle generic PC/SC hardware wallets.
+type Hub struct {
+	scheme string // Protocol scheme prefixing account and wallet URLs.
+
+	context  *pcsc.Client
+	datadir  string
+	pairings map[string]smartcardPairing
+
+	refreshed   time.Time               // Time instance when the list of wallets was last refreshed
+	wallets     map[string]*Wallet      // Mapping from reader names to wallet instances
+	updateFeed  event.Feed              // Event feed to notify wallet additions/removals
+	updateScope event.SubscriptionScope // Subscription scope tracking current live listeners
+	updating    bool                    // Whether the event notification loop is running
+
+	quit chan chan error
+
+	stateLock sync.RWMutex // Protects the internals of the hub from racey access
+}
+
+func (hub *Hub) readPairings() error {
+	hub.pairings = make(map[string]smartcardPairing)
+	pairingFile, err := os.Open(filepath.Join(hub.datadir, "smartcards.json"))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return err
+	}
+
+	pairingData, err := ioutil.ReadAll(pairingFile)
+	if err != nil {
+		return err
+	}
+	var pairings []smartcardPairing
+	if err := json.Unmarshal(pairingData, &pairings); err != nil {
+		return err
+	}
+
+	for _, pairing := range pairings {
+		hub.pairings[string(pairing.PublicKey)] = pairing
+	}
+	return nil
+}
+
+func (hub *Hub) writePairings() error {
+	pairingFile, err := os.OpenFile(filepath.Join(hub.datadir, "smartcards.json"), os.O_RDWR|os.O_CREATE, 0755)
+	if err != nil {
+		return err
+	}
+	defer pairingFile.Close()
+
+	pairings := make([]smartcardPairing, 0, len(hub.pairings))
+	for _, pairing := range hub.pairings {
+		pairings = append(pairings, pairing)
+	}
+
+	pairingData, err := json.Marshal(pairings)
+	if err != nil {
+		return err
+	}
+
+	if _, err := pairingFile.Write(pairingData); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (hub *Hub) pairing(wallet *Wallet) *smartcardPairing {
+	if pairing, ok := hub.pairings[string(wallet.PublicKey)]; ok {
+		return &pairing
+	}
+	return nil
+}
+
+func (hub *Hub) setPairing(wallet *Wallet, pairing *smartcardPairing) error {
+	if pairing == nil {
+		delete(hub.pairings, string(wallet.PublicKey))
+	} else {
+		hub.pairings[string(wallet.PublicKey)] = *pairing
+	}
+	return hub.writePairings()
+}
+
+// NewHub creates a new hardware wallet manager for smartcards.
+func NewHub(daemonPath string, scheme string, datadir string) (*Hub, error) {
+	context, err := pcsc.EstablishContext(daemonPath, pcsc.ScopeSystem)
+	if err != nil {
+		return nil, err
+	}
+	hub := &Hub{
+		scheme:  scheme,
+		context: context,
+		datadir: datadir,
+		wallets: make(map[string]*Wallet),
+		quit:    make(chan chan error),
+	}
+	if err := hub.readPairings(); err != nil {
+		return nil, err
+	}
+	hub.refreshWallets()
+	return hub, nil
+}
+
+// Wallets implements accounts.Backend, returning all the currently tracked smart
+// cards that appear to be hardware wallets.
+func (hub *Hub) Wallets() []accounts.Wallet {
+	// Make sure the list of wallets is up to date
+	hub.refreshWallets()
+
+	hub.stateLock.RLock()
+	defer hub.stateLock.RUnlock()
+
+	cpy := make([]accounts.Wallet, 0, len(hub.wallets))
+	for _, wallet := range hub.wallets {
+		cpy = append(cpy, wallet)
+	}
+	sort.Sort(accounts.WalletsByURL(cpy))
+	return cpy
+}
+
+// refreshWallets scans the devices attached to the machine and updates the
+// list of wallets based on the found devices.
+func (hub *Hub) refreshWallets() {
+	// Don't scan the USB like crazy it the user fetches wallets in a loop
+	hub.stateLock.RLock()
+	elapsed := time.Since(hub.refreshed)
+	hub.stateLock.RUnlock()
+
+	if elapsed < refreshThrottling {
+		return
+	}
+	// Retrieve all the smart card reader to check for cards
+	readers, err := hub.context.ListReaders()
+	if err != nil {
+		// This is a perverted hack, the scard library returns an error if no card
+		// readers are present instead of simply returning an empty list. We don't
+		// want to fill the user's log with errors, so filter those out.
+		if err.Error() != "scard: Cannot find a smart card reader." {
+			log.Error("Failed to enumerate smart card readers", "err", err)
+			return
+		}
+	}
+	// Transform the current list of wallets into the new one
+	hub.stateLock.Lock()
+
+	events := []accounts.WalletEvent{}
+	seen := make(map[string]struct{})
+
+	for _, reader := range readers {
+		// Mark the reader as present
+		seen[reader] = struct{}{}
+
+		// If we alreay know about this card, skip to the next reader, otherwise clean up
+		if wallet, ok := hub.wallets[reader]; ok {
+			if err := wallet.ping(); err == nil {
+				continue
+			}
+			wallet.Close()
+			events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped})
+			delete(hub.wallets, reader)
+		}
+		// New card detected, try to connect to it
+		card, err := hub.context.Connect(reader, pcsc.ShareShared, pcsc.ProtocolAny)
+		if err != nil {
+			log.Debug("Failed to open smart card", "reader", reader, "err", err)
+			continue
+		}
+		wallet := NewWallet(hub, card)
+		if err = wallet.connect(); err != nil {
+			log.Debug("Failed to connect to smart card", "reader", reader, "err", err)
+			card.Disconnect(pcsc.LeaveCard)
+			continue
+		}
+		// Card connected, start tracking in amongs the wallets
+		hub.wallets[reader] = wallet
+		events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletArrived})
+	}
+	// Remove any wallets no longer present
+	for reader, wallet := range hub.wallets {
+		if _, ok := seen[reader]; !ok {
+			wallet.Close()
+			events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped})
+			delete(hub.wallets, reader)
+		}
+	}
+	hub.refreshed = time.Now()
+	hub.stateLock.Unlock()
+
+	for _, event := range events {
+		hub.updateFeed.Send(event)
+	}
+}
+
+// Subscribe implements accounts.Backend, creating an async subscription to
+// receive notifications on the addition or removal of smart card wallets.
+func (hub *Hub) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription {
+	// We need the mutex to reliably start/stop the update loop
+	hub.stateLock.Lock()
+	defer hub.stateLock.Unlock()
+
+	// Subscribe the caller and track the subscriber count
+	sub := hub.updateScope.Track(hub.updateFeed.Subscribe(sink))
+
+	// Subscribers require an active notification loop, start it
+	if !hub.updating {
+		hub.updating = true
+		go hub.updater()
+	}
+	return sub
+}
+
+// updater is responsible for maintaining an up-to-date list of wallets managed
+// by the smart card hub, and for firing wallet addition/removal events.
+func (hub *Hub) updater() {
+	for {
+		// TODO: Wait for a USB hotplug event (not supported yet) or a refresh timeout
+		// <-hub.changes
+		time.Sleep(refreshCycle)
+
+		// Run the wallet refresher
+		hub.refreshWallets()
+
+		// If all our subscribers left, stop the updater
+		hub.stateLock.Lock()
+		if hub.updateScope.Count() == 0 {
+			hub.updating = false
+			hub.stateLock.Unlock()
+			return
+		}
+		hub.stateLock.Unlock()
+	}
+}
diff --git a/accounts/scwallet/securechannel.go b/accounts/scwallet/securechannel.go
new file mode 100644
index 0000000..c1b7cff
--- /dev/null
+++ b/accounts/scwallet/securechannel.go
@@ -0,0 +1,346 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package scwallet
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/sha512"
+	"fmt"
+
+	"github.com/ava-labs/go-ethereum/crypto"
+	pcsc "github.com/gballet/go-libpcsclite"
+	"github.com/wsddn/go-ecdh"
+	"golang.org/x/crypto/pbkdf2"
+	"golang.org/x/text/unicode/norm"
+)
+
+const (
+	maxPayloadSize  = 223
+	pairP1FirstStep = 0
+	pairP1LastStep  = 1
+
+	scSecretLength = 32
+	scBlockSize    = 16
+
+	insOpenSecureChannel    = 0x10
+	insMutuallyAuthenticate = 0x11
+	insPair                 = 0x12
+	insUnpair               = 0x13
+
+	pairingSalt = "Keycard Pairing Password Salt"
+)
+
+// SecureChannelSession enables secure communication with a hardware wallet.
+type SecureChannelSession struct {
+	card          *pcsc.Card // A handle to the smartcard for communication
+	secret        []byte     // A shared secret generated from our ECDSA keys
+	publicKey     []byte     // Our own ephemeral public key
+	PairingKey    []byte     // A permanent shared secret for a pairing, if present
+	sessionEncKey []byte     // The current session encryption key
+	sessionMacKey []byte     // The current session MAC key
+	iv            []byte     // The current IV
+	PairingIndex  uint8      // The pairing index
+}
+
+// NewSecureChannelSession creates a new secure channel for the given card and public key.
+func NewSecureChannelSession(card *pcsc.Card, keyData []byte) (*SecureChannelSession, error) {
+	// Generate an ECDSA keypair for ourselves
+	gen := ecdh.NewEllipticECDH(crypto.S256())
+	private, public, err := gen.GenerateKey(rand.Reader)
+	if err != nil {
+		return nil, err
+	}
+
+	cardPublic, ok := gen.Unmarshal(keyData)
+	if !ok {
+		return nil, fmt.Errorf("Could not unmarshal public key from card")
+	}
+
+	secret, err := gen.GenerateSharedSecret(private, cardPublic)
+	if err != nil {
+		return nil, err
+	}
+
+	return &SecureChannelSession{
+		card:      card,
+		secret:    secret,
+		publicKey: gen.Marshal(public),
+	}, nil
+}
+
+// Pair establishes a new pairing with the smartcard.
+func (s *SecureChannelSession) Pair(pairingPassword []byte) error {
+	secretHash := pbkdf2.Key(norm.NFKD.Bytes(pairingPassword), norm.NFKD.Bytes([]byte(pairingSalt)), 50000, 32, sha256.New)
+
+	challenge := make([]byte, 32)
+	if _, err := rand.Read(challenge); err != nil {
+		return err
+	}
+
+	response, err := s.pair(pairP1FirstStep, challenge)
+	if err != nil {
+		return err
+	}
+
+	md := sha256.New()
+	md.Write(secretHash[:])
+	md.Write(challenge)
+
+	expectedCryptogram := md.Sum(nil)
+	cardCryptogram := response.Data[:32]
+	cardChallenge := response.Data[32:64]
+
+	if !bytes.Equal(expectedCryptogram, cardCryptogram) {
+		return fmt.Errorf("Invalid card cryptogram %v != %v", expectedCryptogram, cardCryptogram)
+	}
+
+	md.Reset()
+	md.Write(secretHash[:])
+	md.Write(cardChallenge)
+	response, err = s.pair(pairP1LastStep, md.Sum(nil))
+	if err != nil {
+		return err
+	}
+
+	md.Reset()
+	md.Write(secretHash[:])
+	md.Write(response.Data[1:])
+	s.PairingKey = md.Sum(nil)
+	s.PairingIndex = response.Data[0]
+
+	return nil
+}
+
+// Unpair disestablishes an existing pairing.
+func (s *SecureChannelSession) Unpair() error {
+	if s.PairingKey == nil {
+		return fmt.Errorf("Cannot unpair: not paired")
+	}
+
+	_, err := s.transmitEncrypted(claSCWallet, insUnpair, s.PairingIndex, 0, []byte{})
+	if err != nil {
+		return err
+	}
+	s.PairingKey = nil
+	// Close channel
+	s.iv = nil
+	return nil
+}
+
+// Open initializes the secure channel.
+func (s *SecureChannelSession) Open() error {
+	if s.iv != nil {
+		return fmt.Errorf("Session already opened")
+	}
+
+	response, err := s.open()
+	if err != nil {
+		return err
+	}
+
+	// Generate the encryption/mac key by hashing our shared secret,
+	// pairing key, and the first bytes returned from the Open APDU.
+	md := sha512.New()
+	md.Write(s.secret)
+	md.Write(s.PairingKey)
+	md.Write(response.Data[:scSecretLength])
+	keyData := md.Sum(nil)
+	s.sessionEncKey = keyData[:scSecretLength]
+	s.sessionMacKey = keyData[scSecretLength : scSecretLength*2]
+
+	// The IV is the last bytes returned from the Open APDU.
+	s.iv = response.Data[scSecretLength:]
+
+	return s.mutuallyAuthenticate()
+}
+
+// mutuallyAuthenticate is an internal method to authenticate both ends of the
+// connection.
+func (s *SecureChannelSession) mutuallyAuthenticate() error {
+	data := make([]byte, scSecretLength)
+	if _, err := rand.Read(data); err != nil {
+		return err
+	}
+
+	response, err := s.transmitEncrypted(claSCWallet, insMutuallyAuthenticate, 0, 0, data)
+	if err != nil {
+		return err
+	}
+	if response.Sw1 != 0x90 || response.Sw2 != 0x00 {
+		return fmt.Errorf("Got unexpected response from MUTUALLY_AUTHENTICATE: 0x%x%x", response.Sw1, response.Sw2)
+	}
+
+	if len(response.Data) != scSecretLength {
+		return fmt.Errorf("Response from MUTUALLY_AUTHENTICATE was %d bytes, expected %d", len(response.Data), scSecretLength)
+	}
+
+	return nil
+}
+
+// open is an internal method that sends an open APDU.
+func (s *SecureChannelSession) open() (*responseAPDU, error) {
+	return transmit(s.card, &commandAPDU{
+		Cla:  claSCWallet,
+		Ins:  insOpenSecureChannel,
+		P1:   s.PairingIndex,
+		P2:   0,
+		Data: s.publicKey,
+		Le:   0,
+	})
+}
+
+// pair is an internal method that sends a pair APDU.
+func (s *SecureChannelSession) pair(p1 uint8, data []byte) (*responseAPDU, error) {
+	return transmit(s.card, &commandAPDU{
+		Cla:  claSCWallet,
+		Ins:  insPair,
+		P1:   p1,
+		P2:   0,
+		Data: data,
+		Le:   0,
+	})
+}
+
+// transmitEncrypted sends an encrypted message, and decrypts and returns the response.
+func (s *SecureChannelSession) transmitEncrypted(cla, ins, p1, p2 byte, data []byte) (*responseAPDU, error) {
+	if s.iv == nil {
+		return nil, fmt.Errorf("Channel not open")
+	}
+
+	data, err := s.encryptAPDU(data)
+	if err != nil {
+		return nil, err
+	}
+	meta := [16]byte{cla, ins, p1, p2, byte(len(data) + scBlockSize)}
+	if err = s.updateIV(meta[:], data); err != nil {
+		return nil, err
+	}
+
+	fulldata := make([]byte, len(s.iv)+len(data))
+	copy(fulldata, s.iv)
+	copy(fulldata[len(s.iv):], data)
+
+	response, err := transmit(s.card, &commandAPDU{
+		Cla:  cla,
+		Ins:  ins,
+		P1:   p1,
+		P2:   p2,
+		Data: fulldata,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	rmeta := [16]byte{byte(len(response.Data))}
+	rmac := response.Data[:len(s.iv)]
+	rdata := response.Data[len(s.iv):]
+	plainData, err := s.decryptAPDU(rdata)
+	if err != nil {
+		return nil, err
+	}
+
+	if err = s.updateIV(rmeta[:], rdata); err != nil {
+		return nil, err
+	}
+	if !bytes.Equal(s.iv, rmac) {
+		return nil, fmt.Errorf("Invalid MAC in response")
+	}
+
+	rapdu := &responseAPDU{}
+	rapdu.deserialize(plainData)
+
+	if rapdu.Sw1 != sw1Ok {
+		return nil, fmt.Errorf("Unexpected response status Cla=0x%x, Ins=0x%x, Sw=0x%x%x", cla, ins, rapdu.Sw1, rapdu.Sw2)
+	}
+
+	return rapdu, nil
+}
+
+// encryptAPDU is an internal method that serializes and encrypts an APDU.
+func (s *SecureChannelSession) encryptAPDU(data []byte) ([]byte, error) {
+	if len(data) > maxPayloadSize {
+		return nil, fmt.Errorf("Payload of %d bytes exceeds maximum of %d", len(data), maxPayloadSize)
+	}
+	data = pad(data, 0x80)
+
+	ret := make([]byte, len(data))
+
+	a, err := aes.NewCipher(s.sessionEncKey)
+	if err != nil {
+		return nil, err
+	}
+	crypter := cipher.NewCBCEncrypter(a, s.iv)
+	crypter.CryptBlocks(ret, data)
+	return ret, nil
+}
+
+// pad applies message padding to a 16 byte boundary.
+func pad(data []byte, terminator byte) []byte {
+	padded := make([]byte, (len(data)/16+1)*16)
+	copy(padded, data)
+	padded[len(data)] = terminator
+	return padded
+}
+
+// decryptAPDU is an internal method that decrypts and deserializes an APDU.
+func (s *SecureChannelSession) decryptAPDU(data []byte) ([]byte, error) {
+	a, err := aes.NewCipher(s.sessionEncKey)
+	if err != nil {
+		return nil, err
+	}
+
+	ret := make([]byte, len(data))
+
+	crypter := cipher.NewCBCDecrypter(a, s.iv)
+	crypter.CryptBlocks(ret, data)
+	return unpad(ret, 0x80)
+}
+
+// unpad strips padding from a message.
+func unpad(data []byte, terminator byte) ([]byte, error) {
+	for i := 1; i <= 16; i++ {
+		switch data[len(data)-i] {
+		case 0:
+			continue
+		case terminator:
+			return data[:len(data)-i], nil
+		default:
+			return nil, fmt.Errorf("Expected end of padding, got %d", data[len(data)-i])
+		}
+	}
+	return nil, fmt.Errorf("Expected end of padding, got 0")
+}
+
+// updateIV is an internal method that updates the initialization vector after
+// each message exchanged.
+func (s *SecureChannelSession) updateIV(meta, data []byte) error {
+	data = pad(data, 0)
+	a, err := aes.NewCipher(s.sessionMacKey)
+	if err != nil {
+		return err
+	}
+	crypter := cipher.NewCBCEncrypter(a, make([]byte, 16))
+	crypter.CryptBlocks(meta, meta)
+	crypter.CryptBlocks(data, data)
+	// The first 16 bytes of the last block is the MAC
+	s.iv = data[len(data)-32 : len(data)-16]
+	return nil
+}
diff --git a/accounts/scwallet/wallet.go b/accounts/scwallet/wallet.go
new file mode 100644
index 0000000..f72e685
--- /dev/null
+++ b/accounts/scwallet/wallet.go
@@ -0,0 +1,1082 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package scwallet
+
+import (
+	"bytes"
+	"context"
+	"crypto/hmac"
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/asn1"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"math/big"
+	"regexp"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/ava-labs/coreth/accounts"
+	"github.com/ava-labs/coreth/core/types"
+	ethereum "github.com/ava-labs/go-ethereum"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/crypto"
+	"github.com/ava-labs/go-ethereum/log"
+	pcsc "github.com/gballet/go-libpcsclite"
+	"github.com/status-im/keycard-go/derivationpath"
+)
+
+// ErrPairingPasswordNeeded is returned if opening the smart card requires pairing with a pairing
+// password. In this case, the calling application should request user input to enter
+// the pairing password and send it back.
+var ErrPairingPasswordNeeded = errors.New("smartcard: pairing password needed")
+
+// ErrPINNeeded is returned if opening the smart card requires a PIN code. In
+// this case, the calling application should request user input to enter the PIN
+// and send it back.
+var ErrPINNeeded = errors.New("smartcard: pin needed")
+
+// ErrPINUnblockNeeded is returned if opening the smart card requires a PIN code,
+// but all PIN attempts have already been exhausted. In this case the calling
+// application should request user input for the PUK and a new PIN code to set
+// fo the card.
+var ErrPINUnblockNeeded = errors.New("smartcard: pin unblock needed")
+
+// ErrAlreadyOpen is returned if the smart card is attempted to be opened, but
+// there is already a paired and unlocked session.
+var ErrAlreadyOpen = errors.New("smartcard: already open")
+
+// ErrPubkeyMismatch is returned if the public key recovered from a signature
+// does not match the one expected by the user.
+var ErrPubkeyMismatch = errors.New("smartcard: recovered public key mismatch")
+
+var (
+	appletAID = []byte{0xA0, 0x00, 0x00, 0x08, 0x04, 0x00, 0x01, 0x01, 0x01}
+	// DerivationSignatureHash is used to derive the public key from the signature of this hash
+	DerivationSignatureHash = sha256.Sum256(common.Hash{}.Bytes())
+)
+
+// List of APDU command-related constants
+const (
+	claISO7816  = 0
+	claSCWallet = 0x80
+
+	insSelect      = 0xA4
+	insGetResponse = 0xC0
+	sw1GetResponse = 0x61
+	sw1Ok          = 0x90
+
+	insVerifyPin  = 0x20
+	insUnblockPin = 0x22
+	insExportKey  = 0xC2
+	insSign       = 0xC0
+	insLoadKey    = 0xD0
+	insDeriveKey  = 0xD1
+	insStatus     = 0xF2
+)
+
+// List of ADPU command parameters
+const (
+	P1DeriveKeyFromMaster  = uint8(0x00)
+	P1DeriveKeyFromParent  = uint8(0x01)
+	P1DeriveKeyFromCurrent = uint8(0x10)
+	statusP1WalletStatus   = uint8(0x00)
+	statusP1Path           = uint8(0x01)
+	signP1PrecomputedHash  = uint8(0x01)
+	signP2OnlyBlock        = uint8(0x81)
+	exportP1Any            = uint8(0x00)
+	exportP2Pubkey         = uint8(0x01)
+)
+
+// Minimum time to wait between self derivation attempts, even it the user is
+// requesting accounts like crazy.
+const selfDeriveThrottling = time.Second
+
+// Wallet represents a smartcard wallet instance.
+type Wallet struct {
+	Hub       *Hub   // A handle to the Hub that instantiated this wallet.
+	PublicKey []byte // The wallet's public key (used for communication and identification, not signing!)
+
+	lock    sync.Mutex // Lock that gates access to struct fields and communication with the card
+	card    *pcsc.Card // A handle to the smartcard interface for the wallet.
+	session *Session   // The secure communication session with the card
+	log     log.Logger // Contextual logger to tag the base with its id
+
+	deriveNextPaths []accounts.DerivationPath // Next derivation paths for account auto-discovery (multiple bases supported)
+	deriveNextAddrs []common.Address          // Next derived account addresses for auto-discovery (multiple bases supported)
+	deriveChain     ethereum.ChainStateReader // Blockchain state reader to discover used account with
+	deriveReq       chan chan struct{}        // Channel to request a self-derivation on
+	deriveQuit      chan chan error           // Channel to terminate the self-deriver with
+}
+
+// NewWallet constructs and returns a new Wallet instance.
+func NewWallet(hub *Hub, card *pcsc.Card) *Wallet {
+	wallet := &Wallet{
+		Hub:  hub,
+		card: card,
+	}
+	return wallet
+}
+
+// transmit sends an APDU to the smartcard and receives and decodes the response.
+// It automatically handles requests by the card to fetch the return data separately,
+// and returns an error if the response status code is not success.
+func transmit(card *pcsc.Card, command *commandAPDU) (*responseAPDU, error) {
+	data, err := command.serialize()
+	if err != nil {
+		return nil, err
+	}
+
+	responseData, _, err := card.Transmit(data)
+	if err != nil {
+		return nil, err
+	}
+
+	response := new(responseAPDU)
+	if err = response.deserialize(responseData); err != nil {
+		return nil, err
+	}
+
+	// Are we being asked to fetch the response separately?
+	if response.Sw1 == sw1GetResponse && (command.Cla != claISO7816 || command.Ins != insGetResponse) {
+		return transmit(card, &commandAPDU{
+			Cla:  claISO7816,
+			Ins:  insGetResponse,
+			P1:   0,
+			P2:   0,
+			Data: nil,
+			Le:   response.Sw2,
+		})
+	}
+
+	if response.Sw1 != sw1Ok {
+		return nil, fmt.Errorf("Unexpected insecure response status Cla=0x%x, Ins=0x%x, Sw=0x%x%x", command.Cla, command.Ins, response.Sw1, response.Sw2)
+	}
+
+	return response, nil
+}
+
+// applicationInfo encodes information about the smartcard application - its
+// instance UID and public key.
+type applicationInfo struct {
+	InstanceUID []byte `asn1:"tag:15"`
+	PublicKey   []byte `asn1:"tag:0"`
+}
+
+// connect connects to the wallet application and establishes a secure channel with it.
+// must be called before any other interaction with the wallet.
+func (w *Wallet) connect() error {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	appinfo, err := w.doselect()
+	if err != nil {
+		return err
+	}
+
+	channel, err := NewSecureChannelSession(w.card, appinfo.PublicKey)
+	if err != nil {
+		return err
+	}
+
+	w.PublicKey = appinfo.PublicKey
+	w.log = log.New("url", w.URL())
+	w.session = &Session{
+		Wallet:  w,
+		Channel: channel,
+	}
+	return nil
+}
+
+// doselect is an internal (unlocked) function to send a SELECT APDU to the card.
+func (w *Wallet) doselect() (*applicationInfo, error) {
+	response, err := transmit(w.card, &commandAPDU{
+		Cla:  claISO7816,
+		Ins:  insSelect,
+		P1:   4,
+		P2:   0,
+		Data: appletAID,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	appinfo := new(applicationInfo)
+	if _, err := asn1.UnmarshalWithParams(response.Data, appinfo, "tag:4"); err != nil {
+		return nil, err
+	}
+	return appinfo, nil
+}
+
+// ping checks the card's status and returns an error if unsuccessful.
+func (w *Wallet) ping() error {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	// We can't ping if not paired
+	if !w.session.paired() {
+		return nil
+	}
+	if _, err := w.session.walletStatus(); err != nil {
+		return err
+	}
+	return nil
+}
+
+// release releases any resources held by an open wallet instance.
+func (w *Wallet) release() error {
+	if w.session != nil {
+		return w.session.release()
+	}
+	return nil
+}
+
+// pair is an internal (unlocked) function for establishing a new pairing
+// with the wallet.
+func (w *Wallet) pair(puk []byte) error {
+	if w.session.paired() {
+		return fmt.Errorf("Wallet already paired")
+	}
+	pairing, err := w.session.pair(puk)
+	if err != nil {
+		return err
+	}
+	if err = w.Hub.setPairing(w, &pairing); err != nil {
+		return err
+	}
+	return w.session.authenticate(pairing)
+}
+
+// Unpair deletes an existing wallet pairing.
+func (w *Wallet) Unpair(pin []byte) error {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	if !w.session.paired() {
+		return fmt.Errorf("wallet %x not paired", w.PublicKey)
+	}
+	if err := w.session.verifyPin(pin); err != nil {
+		return fmt.Errorf("failed to verify pin: %s", err)
+	}
+	if err := w.session.unpair(); err != nil {
+		return fmt.Errorf("failed to unpair: %s", err)
+	}
+	if err := w.Hub.setPairing(w, nil); err != nil {
+		return err
+	}
+	return nil
+}
+
+// URL retrieves the canonical path under which this wallet is reachable. It is
+// user by upper layers to define a sorting order over all wallets from multiple
+// backends.
+func (w *Wallet) URL() accounts.URL {
+	return accounts.URL{
+		Scheme: w.Hub.scheme,
+		Path:   fmt.Sprintf("%x", w.PublicKey[1:5]), // Byte #0 isn't unique; 1:5 covers << 64K cards, bump to 1:9 for << 4M
+	}
+}
+
+// Status returns a textual status to aid the user in the current state of the
+// wallet. It also returns an error indicating any failure the wallet might have
+// encountered.
+func (w *Wallet) Status() (string, error) {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	// If the card is not paired, we can only wait
+	if !w.session.paired() {
+		return "Unpaired, waiting for pairing password", nil
+	}
+	// Yay, we have an encrypted session, retrieve the actual status
+	status, err := w.session.walletStatus()
+	if err != nil {
+		return fmt.Sprintf("Failed: %v", err), err
+	}
+	switch {
+	case !w.session.verified && status.PinRetryCount == 0 && status.PukRetryCount == 0:
+		return fmt.Sprintf("Bricked, waiting for full wipe"), nil
+	case !w.session.verified && status.PinRetryCount == 0:
+		return fmt.Sprintf("Blocked, waiting for PUK (%d attempts left) and new PIN", status.PukRetryCount), nil
+	case !w.session.verified:
+		return fmt.Sprintf("Locked, waiting for PIN (%d attempts left)", status.PinRetryCount), nil
+	case !status.Initialized:
+		return fmt.Sprintf("Empty, waiting for initialization"), nil
+	default:
+		return fmt.Sprintf("Online"), nil
+	}
+}
+
+// Open initializes access to a wallet instance. It is not meant to unlock or
+// decrypt account keys, rather simply to establish a connection to hardware
+// wallets and/or to access derivation seeds.
+//
+// The passphrase parameter may or may not be used by the implementation of a
+// particular wallet instance. The reason there is no passwordless open method
+// is to strive towards a uniform wallet handling, oblivious to the different
+// backend providers.
+//
+// Please note, if you open a wallet, you must close it to release any allocated
+// resources (especially important when working with hardware wallets).
+func (w *Wallet) Open(passphrase string) error {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	// If the session is already open, bail out
+	if w.session.verified {
+		return ErrAlreadyOpen
+	}
+	// If the smart card is not yet paired, attempt to do so either from a previous
+	// pairing key or form the supplied PUK code.
+	if !w.session.paired() {
+		// If a previous pairing exists, only ever try to use that
+		if pairing := w.Hub.pairing(w); pairing != nil {
+			if err := w.session.authenticate(*pairing); err != nil {
+				return fmt.Errorf("failed to authenticate card %x: %s", w.PublicKey[:4], err)
+			}
+			// Pairing still ok, fall through to PIN checks
+		} else {
+			// If no passphrase was supplied, request the PUK from the user
+			if passphrase == "" {
+				return ErrPairingPasswordNeeded
+			}
+			// Attempt to pair the smart card with the user supplied PUK
+			if err := w.pair([]byte(passphrase)); err != nil {
+				return err
+			}
+			// Pairing succeeded, fall through to PIN checks. This will of course fail,
+			// but we can't return ErrPINNeeded directly here becase we don't know whether
+			// a PIN check or a PIN reset is needed.
+			passphrase = ""
+		}
+	}
+	// The smart card was successfully paired, retrieve its status to check whether
+	// PIN verification or unblocking is needed.
+	status, err := w.session.walletStatus()
+	if err != nil {
+		return err
+	}
+	// Request the appropriate next authentication data, or use the one supplied
+	switch {
+	case passphrase == "" && status.PinRetryCount > 0:
+		return ErrPINNeeded
+	case passphrase == "":
+		return ErrPINUnblockNeeded
+	case status.PinRetryCount > 0:
+		if !regexp.MustCompile(`^[0-9]{6,}$`).MatchString(passphrase) {
+			w.log.Error("PIN needs to be at least 6 digits")
+			return ErrPINNeeded
+		}
+		if err := w.session.verifyPin([]byte(passphrase)); err != nil {
+			return err
+		}
+	default:
+		if !regexp.MustCompile(`^[0-9]{12,}$`).MatchString(passphrase) {
+			w.log.Error("PUK needs to be at least 12 digits")
+			return ErrPINUnblockNeeded
+		}
+		if err := w.session.unblockPin([]byte(passphrase)); err != nil {
+			return err
+		}
+	}
+	// Smart card paired and unlocked, initialize and register
+	w.deriveReq = make(chan chan struct{})
+	w.deriveQuit = make(chan chan error)
+
+	go w.selfDerive()
+
+	// Notify anyone listening for wallet events that a new device is accessible
+	go w.Hub.updateFeed.Send(accounts.WalletEvent{Wallet: w, Kind: accounts.WalletOpened})
+
+	return nil
+}
+
+// Close stops and closes the wallet, freeing any resources.
+func (w *Wallet) Close() error {
+	// Ensure the wallet was opened
+	w.lock.Lock()
+	dQuit := w.deriveQuit
+	w.lock.Unlock()
+
+	// Terminate the self-derivations
+	var derr error
+	if dQuit != nil {
+		errc := make(chan error)
+		dQuit <- errc
+		derr = <-errc // Save for later, we *must* close the USB
+	}
+	// Terminate the device connection
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	w.deriveQuit = nil
+	w.deriveReq = nil
+
+	if err := w.release(); err != nil {
+		return err
+	}
+	return derr
+}
+
+// selfDerive is an account derivation loop that upon request attempts to find
+// new non-zero accounts.
+func (w *Wallet) selfDerive() {
+	w.log.Debug("Smart card wallet self-derivation started")
+	defer w.log.Debug("Smart card wallet self-derivation stopped")
+
+	// Execute self-derivations until termination or error
+	var (
+		reqc chan struct{}
+		errc chan error
+		err  error
+	)
+	for errc == nil && err == nil {
+		// Wait until either derivation or termination is requested
+		select {
+		case errc = <-w.deriveQuit:
+			// Termination requested
+			continue
+		case reqc = <-w.deriveReq:
+			// Account discovery requested
+		}
+		// Derivation needs a chain and device access, skip if either unavailable
+		w.lock.Lock()
+		if w.session == nil || w.deriveChain == nil {
+			w.lock.Unlock()
+			reqc <- struct{}{}
+			continue
+		}
+		pairing := w.Hub.pairing(w)
+
+		// Device lock obtained, derive the next batch of accounts
+		var (
+			paths   []accounts.DerivationPath
+			nextAcc accounts.Account
+
+			nextPaths = append([]accounts.DerivationPath{}, w.deriveNextPaths...)
+			nextAddrs = append([]common.Address{}, w.deriveNextAddrs...)
+
+			context = context.Background()
+		)
+		for i := 0; i < len(nextAddrs); i++ {
+			for empty := false; !empty; {
+				// Retrieve the next derived Ethereum account
+				if nextAddrs[i] == (common.Address{}) {
+					if nextAcc, err = w.session.derive(nextPaths[i]); err != nil {
+						w.log.Warn("Smartcard wallet account derivation failed", "err", err)
+						break
+					}
+					nextAddrs[i] = nextAcc.Address
+				}
+				// Check the account's status against the current chain state
+				var (
+					balance *big.Int
+					nonce   uint64
+				)
+				balance, err = w.deriveChain.BalanceAt(context, nextAddrs[i], nil)
+				if err != nil {
+					w.log.Warn("Smartcard wallet balance retrieval failed", "err", err)
+					break
+				}
+				nonce, err = w.deriveChain.NonceAt(context, nextAddrs[i], nil)
+				if err != nil {
+					w.log.Warn("Smartcard wallet nonce retrieval failed", "err", err)
+					break
+				}
+				// If the next account is empty, stop self-derivation, but add for the last base path
+				if balance.Sign() == 0 && nonce == 0 {
+					empty = true
+					if i < len(nextAddrs)-1 {
+						break
+					}
+				}
+				// We've just self-derived a new account, start tracking it locally
+				path := make(accounts.DerivationPath, len(nextPaths[i]))
+				copy(path[:], nextPaths[i][:])
+				paths = append(paths, path)
+
+				// Display a log message to the user for new (or previously empty accounts)
+				if _, known := pairing.Accounts[nextAddrs[i]]; !known || !empty || nextAddrs[i] != w.deriveNextAddrs[i] {
+					w.log.Info("Smartcard wallet discovered new account", "address", nextAddrs[i], "path", path, "balance", balance, "nonce", nonce)
+				}
+				pairing.Accounts[nextAddrs[i]] = path
+
+				// Fetch the next potential account
+				if !empty {
+					nextAddrs[i] = common.Address{}
+					nextPaths[i][len(nextPaths[i])-1]++
+				}
+			}
+		}
+		// If there are new accounts, write them out
+		if len(paths) > 0 {
+			err = w.Hub.setPairing(w, pairing)
+		}
+		// Shift the self-derivation forward
+		w.deriveNextAddrs = nextAddrs
+		w.deriveNextPaths = nextPaths
+
+		// Self derivation complete, release device lock
+		w.lock.Unlock()
+
+		// Notify the user of termination and loop after a bit of time (to avoid trashing)
+		reqc <- struct{}{}
+		if err == nil {
+			select {
+			case errc = <-w.deriveQuit:
+				// Termination requested, abort
+			case <-time.After(selfDeriveThrottling):
+				// Waited enough, willing to self-derive again
+			}
+		}
+	}
+	// In case of error, wait for termination
+	if err != nil {
+		w.log.Debug("Smartcard wallet self-derivation failed", "err", err)
+		errc = <-w.deriveQuit
+	}
+	errc <- err
+}
+
+// Accounts retrieves the list of signing accounts the wallet is currently aware
+// of. For hierarchical deterministic wallets, the list will not be exhaustive,
+// rather only contain the accounts explicitly pinned during account derivation.
+func (w *Wallet) Accounts() []accounts.Account {
+	// Attempt self-derivation if it's running
+	reqc := make(chan struct{}, 1)
+	select {
+	case w.deriveReq <- reqc:
+		// Self-derivation request accepted, wait for it
+		<-reqc
+	default:
+		// Self-derivation offline, throttled or busy, skip
+	}
+
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	if pairing := w.Hub.pairing(w); pairing != nil {
+		ret := make([]accounts.Account, 0, len(pairing.Accounts))
+		for address, path := range pairing.Accounts {
+			ret = append(ret, w.makeAccount(address, path))
+		}
+		sort.Sort(accounts.AccountsByURL(ret))
+		return ret
+	}
+	return nil
+}
+
+func (w *Wallet) makeAccount(address common.Address, path accounts.DerivationPath) accounts.Account {
+	return accounts.Account{
+		Address: address,
+		URL: accounts.URL{
+			Scheme: w.Hub.scheme,
+			Path:   fmt.Sprintf("%x/%s", w.PublicKey[1:3], path.String()),
+		},
+	}
+}
+
+// Contains returns whether an account is part of this particular wallet or not.
+func (w *Wallet) Contains(account accounts.Account) bool {
+	if pairing := w.Hub.pairing(w); pairing != nil {
+		_, ok := pairing.Accounts[account.Address]
+		return ok
+	}
+	return false
+}
+
+// Initialize installs a keypair generated from the provided key into the wallet.
+func (w *Wallet) Initialize(seed []byte) error {
+	go w.selfDerive()
+	// DO NOT lock at this stage, as the initialize
+	// function relies on Status()
+	return w.session.initialize(seed)
+}
+
+// Derive attempts to explicitly derive a hierarchical deterministic account at
+// the specified derivation path. If requested, the derived account will be added
+// to the wallet's tracked account list.
+func (w *Wallet) Derive(path accounts.DerivationPath, pin bool) (accounts.Account, error) {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	account, err := w.session.derive(path)
+	if err != nil {
+		return accounts.Account{}, err
+	}
+
+	if pin {
+		pairing := w.Hub.pairing(w)
+		pairing.Accounts[account.Address] = path
+		if err := w.Hub.setPairing(w, pairing); err != nil {
+			return accounts.Account{}, err
+		}
+	}
+
+	return account, nil
+}
+
+// SelfDerive sets a base account derivation path from which the wallet attempts
+// to discover non zero accounts and automatically add them to list of tracked
+// accounts.
+//
+// Note, self derivaton will increment the last component of the specified path
+// opposed to decending into a child path to allow discovering accounts starting
+// from non zero components.
+//
+// Some hardware wallets switched derivation paths through their evolution, so
+// this method supports providing multiple bases to discover old user accounts
+// too. Only the last base will be used to derive the next empty account.
+//
+// You can disable automatic account discovery by calling SelfDerive with a nil
+// chain state reader.
+func (w *Wallet) SelfDerive(bases []accounts.DerivationPath, chain ethereum.ChainStateReader) {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	w.deriveNextPaths = make([]accounts.DerivationPath, len(bases))
+	for i, base := range bases {
+		w.deriveNextPaths[i] = make(accounts.DerivationPath, len(base))
+		copy(w.deriveNextPaths[i][:], base[:])
+	}
+	w.deriveNextAddrs = make([]common.Address, len(bases))
+	w.deriveChain = chain
+}
+
+// SignData requests the wallet to sign the hash of the given data.
+//
+// It looks up the account specified either solely via its address contained within,
+// or optionally with the aid of any location metadata from the embedded URL field.
+//
+// If the wallet requires additional authentication to sign the request (e.g.
+// a password to decrypt the account, or a PIN code o verify the transaction),
+// an AuthNeededError instance will be returned, containing infos for the user
+// about which fields or actions are needed. The user may retry by providing
+// the needed details via SignDataWithPassphrase, or by other means (e.g. unlock
+// the account in a keystore).
+func (w *Wallet) SignData(account accounts.Account, mimeType string, data []byte) ([]byte, error) {
+	return w.signHash(account, crypto.Keccak256(data))
+}
+
+func (w *Wallet) signHash(account accounts.Account, hash []byte) ([]byte, error) {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	path, err := w.findAccountPath(account)
+	if err != nil {
+		return nil, err
+	}
+
+	return w.session.sign(path, hash)
+}
+
+// SignTx requests the wallet to sign the given transaction.
+//
+// It looks up the account specified either solely via its address contained within,
+// or optionally with the aid of any location metadata from the embedded URL field.
+//
+// If the wallet requires additional authentication to sign the request (e.g.
+// a password to decrypt the account, or a PIN code o verify the transaction),
+// an AuthNeededError instance will be returned, containing infos for the user
+// about which fields or actions are needed. The user may retry by providing
+// the needed details via SignTxWithPassphrase, or by other means (e.g. unlock
+// the account in a keystore).
+func (w *Wallet) SignTx(account accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	signer := types.NewEIP155Signer(chainID)
+	hash := signer.Hash(tx)
+	sig, err := w.signHash(account, hash[:])
+	if err != nil {
+		return nil, err
+	}
+	return tx.WithSignature(signer, sig)
+}
+
+// SignDataWithPassphrase requests the wallet to sign the given hash with the
+// given passphrase as extra authentication information.
+//
+// It looks up the account specified either solely via its address contained within,
+// or optionally with the aid of any location metadata from the embedded URL field.
+func (w *Wallet) SignDataWithPassphrase(account accounts.Account, passphrase, mimeType string, data []byte) ([]byte, error) {
+	return w.signHashWithPassphrase(account, passphrase, crypto.Keccak256(data))
+}
+
+func (w *Wallet) signHashWithPassphrase(account accounts.Account, passphrase string, hash []byte) ([]byte, error) {
+	if !w.session.verified {
+		if err := w.Open(passphrase); err != nil {
+			return nil, err
+		}
+	}
+
+	return w.signHash(account, hash)
+}
+
+// SignText requests the wallet to sign the hash of a given piece of data, prefixed
+// by the Ethereum prefix scheme
+// It looks up the account specified either solely via its address contained within,
+// or optionally with the aid of any location metadata from the embedded URL field.
+//
+// If the wallet requires additional authentication to sign the request (e.g.
+// a password to decrypt the account, or a PIN code o verify the transaction),
+// an AuthNeededError instance will be returned, containing infos for the user
+// about which fields or actions are needed. The user may retry by providing
+// the needed details via SignHashWithPassphrase, or by other means (e.g. unlock
+// the account in a keystore).
+func (w *Wallet) SignText(account accounts.Account, text []byte) ([]byte, error) {
+	return w.signHash(account, accounts.TextHash(text))
+}
+
+// SignTextWithPassphrase implements accounts.Wallet, attempting to sign the
+// given hash with the given account using passphrase as extra authentication
+func (w *Wallet) SignTextWithPassphrase(account accounts.Account, passphrase string, text []byte) ([]byte, error) {
+	return w.signHashWithPassphrase(account, passphrase, crypto.Keccak256(accounts.TextHash(text)))
+}
+
+// SignTxWithPassphrase requests the wallet to sign the given transaction, with the
+// given passphrase as extra authentication information.
+//
+// It looks up the account specified either solely via its address contained within,
+// or optionally with the aid of any location metadata from the embedded URL field.
+func (w *Wallet) SignTxWithPassphrase(account accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	if !w.session.verified {
+		if err := w.Open(passphrase); err != nil {
+			return nil, err
+		}
+	}
+	return w.SignTx(account, tx, chainID)
+}
+
+// findAccountPath returns the derivation path for the provided account.
+// It first checks for the address in the list of pinned accounts, and if it is
+// not found, attempts to parse the derivation path from the account's URL.
+func (w *Wallet) findAccountPath(account accounts.Account) (accounts.DerivationPath, error) {
+	pairing := w.Hub.pairing(w)
+	if path, ok := pairing.Accounts[account.Address]; ok {
+		return path, nil
+	}
+
+	// Look for the path in the URL
+	if account.URL.Scheme != w.Hub.scheme {
+		return nil, fmt.Errorf("Scheme %s does not match wallet scheme %s", account.URL.Scheme, w.Hub.scheme)
+	}
+
+	parts := strings.SplitN(account.URL.Path, "/", 2)
+	if len(parts) != 2 {
+		return nil, fmt.Errorf("Invalid URL format: %s", account.URL)
+	}
+
+	if parts[0] != fmt.Sprintf("%x", w.PublicKey[1:3]) {
+		return nil, fmt.Errorf("URL %s is not for this wallet", account.URL)
+	}
+
+	return accounts.ParseDerivationPath(parts[1])
+}
+
+// Session represents a secured communication session with the wallet.
+type Session struct {
+	Wallet   *Wallet               // A handle to the wallet that opened the session
+	Channel  *SecureChannelSession // A secure channel for encrypted messages
+	verified bool                  // Whether the pin has been verified in this session.
+}
+
+// pair establishes a new pairing over this channel, using the provided secret.
+func (s *Session) pair(secret []byte) (smartcardPairing, error) {
+	err := s.Channel.Pair(secret)
+	if err != nil {
+		return smartcardPairing{}, err
+	}
+
+	return smartcardPairing{
+		PublicKey:    s.Wallet.PublicKey,
+		PairingIndex: s.Channel.PairingIndex,
+		PairingKey:   s.Channel.PairingKey,
+		Accounts:     make(map[common.Address]accounts.DerivationPath),
+	}, nil
+}
+
+// unpair deletes an existing pairing.
+func (s *Session) unpair() error {
+	if !s.verified {
+		return fmt.Errorf("Unpair requires that the PIN be verified")
+	}
+	return s.Channel.Unpair()
+}
+
+// verifyPin unlocks a wallet with the provided pin.
+func (s *Session) verifyPin(pin []byte) error {
+	if _, err := s.Channel.transmitEncrypted(claSCWallet, insVerifyPin, 0, 0, pin); err != nil {
+		return err
+	}
+	s.verified = true
+	return nil
+}
+
+// unblockPin unblocks a wallet with the provided puk and resets the pin to the
+// new one specified.
+func (s *Session) unblockPin(pukpin []byte) error {
+	if _, err := s.Channel.transmitEncrypted(claSCWallet, insUnblockPin, 0, 0, pukpin); err != nil {
+		return err
+	}
+	s.verified = true
+	return nil
+}
+
+// release releases resources associated with the channel.
+func (s *Session) release() error {
+	return s.Wallet.card.Disconnect(pcsc.LeaveCard)
+}
+
+// paired returns true if a valid pairing exists.
+func (s *Session) paired() bool {
+	return s.Channel.PairingKey != nil
+}
+
+// authenticate uses an existing pairing to establish a secure channel.
+func (s *Session) authenticate(pairing smartcardPairing) error {
+	if !bytes.Equal(s.Wallet.PublicKey, pairing.PublicKey) {
+		return fmt.Errorf("Cannot pair using another wallet's pairing; %x != %x", s.Wallet.PublicKey, pairing.PublicKey)
+	}
+	s.Channel.PairingKey = pairing.PairingKey
+	s.Channel.PairingIndex = pairing.PairingIndex
+	return s.Channel.Open()
+}
+
+// walletStatus describes a smartcard wallet's status information.
+type walletStatus struct {
+	PinRetryCount int  // Number of remaining PIN retries
+	PukRetryCount int  // Number of remaining PUK retries
+	Initialized   bool // Whether the card has been initialized with a private key
+}
+
+// walletStatus fetches the wallet's status from the card.
+func (s *Session) walletStatus() (*walletStatus, error) {
+	response, err := s.Channel.transmitEncrypted(claSCWallet, insStatus, statusP1WalletStatus, 0, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	status := new(walletStatus)
+	if _, err := asn1.UnmarshalWithParams(response.Data, status, "tag:3"); err != nil {
+		return nil, err
+	}
+	return status, nil
+}
+
+// derivationPath fetches the wallet's current derivation path from the card.
+func (s *Session) derivationPath() (accounts.DerivationPath, error) {
+	response, err := s.Channel.transmitEncrypted(claSCWallet, insStatus, statusP1Path, 0, nil)
+	if err != nil {
+		return nil, err
+	}
+	buf := bytes.NewReader(response.Data)
+	path := make(accounts.DerivationPath, len(response.Data)/4)
+	return path, binary.Read(buf, binary.BigEndian, &path)
+}
+
+// initializeData contains data needed to initialize the smartcard wallet.
+type initializeData struct {
+	PublicKey  []byte `asn1:"tag:0"`
+	PrivateKey []byte `asn1:"tag:1"`
+	ChainCode  []byte `asn1:"tag:2"`
+}
+
+// initialize initializes the card with new key data.
+func (s *Session) initialize(seed []byte) error {
+	// Check that the wallet isn't currently initialized,
+	// otherwise the key would be overwritten.
+	status, err := s.Wallet.Status()
+	if err != nil {
+		return err
+	}
+	if status == "Online" {
+		return fmt.Errorf("card is already initialized, cowardly refusing to proceed")
+	}
+
+	s.Wallet.lock.Lock()
+	defer s.Wallet.lock.Unlock()
+
+	// HMAC the seed to produce the private key and chain code
+	mac := hmac.New(sha512.New, []byte("Bitcoin seed"))
+	mac.Write(seed)
+	seed = mac.Sum(nil)
+
+	key, err := crypto.ToECDSA(seed[:32])
+	if err != nil {
+		return err
+	}
+
+	id := initializeData{}
+	id.PublicKey = crypto.FromECDSAPub(&key.PublicKey)
+	id.PrivateKey = seed[:32]
+	id.ChainCode = seed[32:]
+	data, err := asn1.Marshal(id)
+	if err != nil {
+		return err
+	}
+
+	// Nasty hack to force the top-level struct tag to be context-specific
+	data[0] = 0xA1
+
+	_, err = s.Channel.transmitEncrypted(claSCWallet, insLoadKey, 0x02, 0, data)
+	return err
+}
+
+// derive derives a new HD key path on the card.
+func (s *Session) derive(path accounts.DerivationPath) (accounts.Account, error) {
+	startingPoint, path, err := derivationpath.Decode(path.String())
+	if err != nil {
+		return accounts.Account{}, err
+	}
+
+	var p1 uint8
+	switch startingPoint {
+	case derivationpath.StartingPointMaster:
+		p1 = P1DeriveKeyFromMaster
+	case derivationpath.StartingPointParent:
+		p1 = P1DeriveKeyFromParent
+	case derivationpath.StartingPointCurrent:
+		p1 = P1DeriveKeyFromCurrent
+	default:
+		return accounts.Account{}, fmt.Errorf("invalid startingPoint %d", startingPoint)
+	}
+
+	data := new(bytes.Buffer)
+	for _, segment := range path {
+		if err := binary.Write(data, binary.BigEndian, segment); err != nil {
+			return accounts.Account{}, err
+		}
+	}
+
+	_, err = s.Channel.transmitEncrypted(claSCWallet, insDeriveKey, p1, 0, data.Bytes())
+	if err != nil {
+		return accounts.Account{}, err
+	}
+
+	response, err := s.Channel.transmitEncrypted(claSCWallet, insSign, 0, 0, DerivationSignatureHash[:])
+	if err != nil {
+		return accounts.Account{}, err
+	}
+
+	sigdata := new(signatureData)
+	if _, err := asn1.UnmarshalWithParams(response.Data, sigdata, "tag:0"); err != nil {
+		return accounts.Account{}, err
+	}
+	rbytes, sbytes := sigdata.Signature.R.Bytes(), sigdata.Signature.S.Bytes()
+	sig := make([]byte, 65)
+	copy(sig[32-len(rbytes):32], rbytes)
+	copy(sig[64-len(sbytes):64], sbytes)
+
+	if err := confirmPublicKey(sig, sigdata.PublicKey); err != nil {
+		return accounts.Account{}, err
+	}
+	pub, err := crypto.UnmarshalPubkey(sigdata.PublicKey)
+	if err != nil {
+		return accounts.Account{}, err
+	}
+	return s.Wallet.makeAccount(crypto.PubkeyToAddress(*pub), path), nil
+}
+
+// keyExport contains information on an exported keypair.
+type keyExport struct {
+	PublicKey  []byte `asn1:"tag:0"`
+	PrivateKey []byte `asn1:"tag:1,optional"`
+}
+
+// publicKey returns the public key for the current derivation path.
+func (s *Session) publicKey() ([]byte, error) {
+	response, err := s.Channel.transmitEncrypted(claSCWallet, insExportKey, exportP1Any, exportP2Pubkey, nil)
+	if err != nil {
+		return nil, err
+	}
+	keys := new(keyExport)
+	if _, err := asn1.UnmarshalWithParams(response.Data, keys, "tag:1"); err != nil {
+		return nil, err
+	}
+	return keys.PublicKey, nil
+}
+
+// signatureData contains information on a signature - the signature itself and
+// the corresponding public key.
+type signatureData struct {
+	PublicKey []byte `asn1:"tag:0"`
+	Signature struct {
+		R *big.Int
+		S *big.Int
+	}
+}
+
+// sign asks the card to sign a message, and returns a valid signature after
+// recovering the v value.
+func (s *Session) sign(path accounts.DerivationPath, hash []byte) ([]byte, error) {
+	startTime := time.Now()
+	_, err := s.derive(path)
+	if err != nil {
+		return nil, err
+	}
+	deriveTime := time.Now()
+
+	response, err := s.Channel.transmitEncrypted(claSCWallet, insSign, signP1PrecomputedHash, signP2OnlyBlock, hash)
+	if err != nil {
+		return nil, err
+	}
+	sigdata := new(signatureData)
+	if _, err := asn1.UnmarshalWithParams(response.Data, sigdata, "tag:0"); err != nil {
+		return nil, err
+	}
+	// Serialize the signature
+	rbytes, sbytes := sigdata.Signature.R.Bytes(), sigdata.Signature.S.Bytes()
+	sig := make([]byte, 65)
+	copy(sig[32-len(rbytes):32], rbytes)
+	copy(sig[64-len(sbytes):64], sbytes)
+
+	// Recover the V value.
+	sig, err = makeRecoverableSignature(hash, sig, sigdata.PublicKey)
+	if err != nil {
+		return nil, err
+	}
+	log.Debug("Signed using smartcard", "deriveTime", deriveTime.Sub(startTime), "signingTime", time.Since(deriveTime))
+
+	return sig, nil
+}
+
+// confirmPublicKey confirms that the given signature belongs to the specified key.
+func confirmPublicKey(sig, pubkey []byte) error {
+	_, err := makeRecoverableSignature(DerivationSignatureHash[:], sig, pubkey)
+	return err
+}
+
+// makeRecoverableSignature uses a signature and an expected public key to
+// recover the v value and produce a recoverable signature.
+func makeRecoverableSignature(hash, sig, expectedPubkey []byte) ([]byte, error) {
+	var libraryError error
+	for v := 0; v < 2; v++ {
+		sig[64] = byte(v)
+		if pubkey, err := crypto.Ecrecover(hash, sig); err == nil {
+			if bytes.Equal(pubkey, expectedPubkey) {
+				return sig, nil
+			}
+		} else {
+			libraryError = err
+		}
+	}
+	if libraryError != nil {
+		return nil, libraryError
+	}
+	return nil, ErrPubkeyMismatch
+}
diff --git a/accounts/sort.go b/accounts/sort.go
new file mode 100644
index 0000000..f467621
--- /dev/null
+++ b/accounts/sort.go
@@ -0,0 +1,31 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+// AccountsByURL implements sort.Interface for []Account based on the URL field.
+type AccountsByURL []Account
+
+func (a AccountsByURL) Len() int           { return len(a) }
+func (a AccountsByURL) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a AccountsByURL) Less(i, j int) bool { return a[i].URL.Cmp(a[j].URL) < 0 }
+
+// WalletsByURL implements sort.Interface for []Wallet based on the URL field.
+type WalletsByURL []Wallet
+
+func (w WalletsByURL) Len() int           { return len(w) }
+func (w WalletsByURL) Swap(i, j int)      { w[i], w[j] = w[j], w[i] }
+func (w WalletsByURL) Less(i, j int) bool { return w[i].URL().Cmp(w[j].URL()) < 0 }
diff --git a/accounts/url.go b/accounts/url.go
new file mode 100644
index 0000000..a5add10
--- /dev/null
+++ b/accounts/url.go
@@ -0,0 +1,104 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// URL represents the canonical identification URL of a wallet or account.
+//
+// It is a simplified version of url.URL, with the important limitations (which
+// are considered features here) that it contains value-copyable components only,
+// as well as that it doesn't do any URL encoding/decoding of special characters.
+//
+// The former is important to allow an account to be copied without leaving live
+// references to the original version, whereas the latter is important to ensure
+// one single canonical form opposed to many allowed ones by the RFC 3986 spec.
+//
+// As such, these URLs should not be used outside of the scope of an Ethereum
+// wallet or account.
+type URL struct {
+	Scheme string // Protocol scheme to identify a capable account backend
+	Path   string // Path for the backend to identify a unique entity
+}
+
+// parseURL converts a user supplied URL into the accounts specific structure.
+func parseURL(url string) (URL, error) {
+	parts := strings.Split(url, "://")
+	if len(parts) != 2 || parts[0] == "" {
+		return URL{}, errors.New("protocol scheme missing")
+	}
+	return URL{
+		Scheme: parts[0],
+		Path:   parts[1],
+	}, nil
+}
+
+// String implements the stringer interface.
+func (u URL) String() string {
+	if u.Scheme != "" {
+		return fmt.Sprintf("%s://%s", u.Scheme, u.Path)
+	}
+	return u.Path
+}
+
+// TerminalString implements the log.TerminalStringer interface.
+func (u URL) TerminalString() string {
+	url := u.String()
+	if len(url) > 32 {
+		return url[:31] + "…"
+	}
+	return url
+}
+
+// MarshalJSON implements the json.Marshaller interface.
+func (u URL) MarshalJSON() ([]byte, error) {
+	return json.Marshal(u.String())
+}
+
+// UnmarshalJSON parses url.
+func (u *URL) UnmarshalJSON(input []byte) error {
+	var textURL string
+	err := json.Unmarshal(input, &textURL)
+	if err != nil {
+		return err
+	}
+	url, err := parseURL(textURL)
+	if err != nil {
+		return err
+	}
+	u.Scheme = url.Scheme
+	u.Path = url.Path
+	return nil
+}
+
+// Cmp compares x and y and returns:
+//
+//   -1 if x <  y
+//    0 if x == y
+//   +1 if x >  y
+//
+func (u URL) Cmp(url URL) int {
+	if u.Scheme == url.Scheme {
+		return strings.Compare(u.Path, url.Path)
+	}
+	return strings.Compare(u.Scheme, url.Scheme)
+}