diff --git a/core/types/block.go b/core/types/block.go
index 9a97061b77..80fc238aa4 100644
--- a/core/types/block.go
+++ b/core/types/block.go
@@ -1,7 +1,6 @@
 package types
 
 import (
-	"bytes"
 	"encoding/binary"
 	"fmt"
 	"math/big"
@@ -156,9 +155,9 @@ func (self *Block) Transactions() Transactions {
 	return self.transactions
 }
 
-func (self *Block) Transaction(hash []byte) *Transaction {
+func (self *Block) Transaction(hash common.Hash) *Transaction {
 	for _, transaction := range self.transactions {
-		if bytes.Equal(hash, transaction.Hash()) {
+		if transaction.Hash() == hash {
 			return transaction
 		}
 	}
diff --git a/core/types/transaction.go b/core/types/transaction.go
index dcd48af119..d55c5d5ae0 100644
--- a/core/types/transaction.go
+++ b/core/types/transaction.go
@@ -2,13 +2,13 @@ package types
 
 import (
 	"bytes"
-	"crypto/ecdsa"
 	"fmt"
 	"math/big"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/crypto/secp256k1"
-	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto/sha3"
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
@@ -20,7 +20,7 @@ type Transaction struct {
 	AccountNonce uint64
 	Price        *big.Int
 	GasLimit     *big.Int
-	Recipient    []byte
+	Recipient    common.Address
 	Amount       *big.Int
 	Payload      []byte
 	V            byte
@@ -28,31 +28,24 @@ type Transaction struct {
 }
 
 func NewContractCreationTx(Amount, gasAmount, price *big.Int, data []byte) *Transaction {
-	return NewTransactionMessage(nil, Amount, gasAmount, price, data)
+	return NewTransactionMessage(common.Address{}, Amount, gasAmount, price, data)
 }
 
-func NewTransactionMessage(to []byte, Amount, gasAmount, price *big.Int, data []byte) *Transaction {
+func NewTransactionMessage(to common.Address, Amount, gasAmount, price *big.Int, data []byte) *Transaction {
 	return &Transaction{Recipient: to, Amount: Amount, Price: price, GasLimit: gasAmount, Payload: data}
 }
 
 func NewTransactionFromBytes(data []byte) *Transaction {
-	tx := &Transaction{}
-	tx.RlpDecode(data)
-
+	tx := new(Transaction)
+	rlp.Decode(bytes.NewReader(data), tx)
 	return tx
 }
 
-func NewTransactionFromAmount(val *common.Value) *Transaction {
-	tx := &Transaction{}
-	tx.RlpValueDecode(val)
-
-	return tx
-}
-
-func (tx *Transaction) Hash() []byte {
-	data := []interface{}{tx.AccountNonce, tx.Price, tx.GasLimit, tx.Recipient, tx.Amount, tx.Payload}
-
-	return crypto.Sha3(common.Encode(data))
+func (tx *Transaction) Hash() (a common.Hash) {
+	h := sha3.NewKeccak256()
+	rlp.Encode(h, []interface{}{tx.AccountNonce, tx.Price, tx.GasLimit, tx.Recipient, tx.Amount, tx.Payload})
+	h.Sum(a[:])
+	return a
 }
 
 func (self *Transaction) Data() []byte {
@@ -79,11 +72,11 @@ func (self *Transaction) SetNonce(AccountNonce uint64) {
 	self.AccountNonce = AccountNonce
 }
 
-func (self *Transaction) From() []byte {
+func (self *Transaction) From() common.Address {
 	return self.sender()
 }
 
-func (self *Transaction) To() []byte {
+func (self *Transaction) To() common.Address {
 	return self.Recipient
 }
 
@@ -97,48 +90,31 @@ func (tx *Transaction) Curve() (v byte, r []byte, s []byte) {
 
 func (tx *Transaction) Signature(key []byte) []byte {
 	hash := tx.Hash()
-
-	sig, _ := secp256k1.Sign(hash, key)
-
+	sig, _ := secp256k1.Sign(hash[:], key)
 	return sig
 }
 
 func (tx *Transaction) PublicKey() []byte {
 	hash := tx.Hash()
-
 	v, r, s := tx.Curve()
-
 	sig := append(r, s...)
 	sig = append(sig, v-27)
 
 	//pubkey := crypto.Ecrecover(append(hash, sig...))
-	pubkey, _ := secp256k1.RecoverPubkey(hash, sig)
-
+	pubkey, _ := secp256k1.RecoverPubkey(hash[:], sig)
 	return pubkey
 }
 
-func (tx *Transaction) sender() []byte {
+func (tx *Transaction) sender() (a common.Address) {
 	pubkey := tx.PublicKey()
 
 	// Validate the returned key.
 	// Return nil if public key isn't in full format
 	if len(pubkey) == 0 || pubkey[0] != 4 {
-		return nil
+		return a
 	}
-
-	return crypto.Sha3(pubkey[1:])[12:]
-}
-
-// TODO: deprecate after new accounts & key stores are integrated
-func (tx *Transaction) Sign(privk []byte) error {
-
-	sig := tx.Signature(privk)
-
-	tx.R = sig[:32]
-	tx.S = sig[32:64]
-	tx.V = sig[64] + 27
-
-	return nil
+	copy(a[:], crypto.Sha3(pubkey[1:]))
+	return a
 }
 
 func (tx *Transaction) SetSignatureValues(sig []byte) error {
@@ -148,36 +124,17 @@ func (tx *Transaction) SetSignatureValues(sig []byte) error {
 	return nil
 }
 
-func (tx *Transaction) SignECDSA(key *ecdsa.PrivateKey) error {
-	return tx.Sign(crypto.FromECDSA(key))
-}
-
+// TODO: remove
 func (tx *Transaction) RlpData() interface{} {
 	data := []interface{}{tx.AccountNonce, tx.Price, tx.GasLimit, tx.Recipient, tx.Amount, tx.Payload}
-
 	return append(data, tx.V, new(big.Int).SetBytes(tx.R).Bytes(), new(big.Int).SetBytes(tx.S).Bytes())
 }
 
+// TODO: remove
 func (tx *Transaction) RlpEncode() []byte {
 	return common.Encode(tx)
 }
 
-func (tx *Transaction) RlpDecode(data []byte) {
-	rlp.Decode(bytes.NewReader(data), tx)
-}
-
-func (tx *Transaction) RlpValueDecode(decoder *common.Value) {
-	tx.AccountNonce = decoder.Get(0).Uint()
-	tx.Price = decoder.Get(1).BigInt()
-	tx.GasLimit = decoder.Get(2).BigInt()
-	tx.Recipient = decoder.Get(3).Bytes()
-	tx.Amount = decoder.Get(4).BigInt()
-	tx.Payload = decoder.Get(5).Bytes()
-	tx.V = decoder.Get(6).Byte()
-	tx.R = decoder.Get(7).Bytes()
-	tx.S = decoder.Get(8).Bytes()
-}
-
 func (tx *Transaction) String() string {
 	return fmt.Sprintf(`
 	TX(%x)
@@ -213,6 +170,7 @@ func (tx *Transaction) String() string {
 // Transaction slice type for basic sorting
 type Transactions []*Transaction
 
+// TODO: remove
 func (self Transactions) RlpData() interface{} {
 	// Marshal the transactions of this block
 	enc := make([]interface{}, len(self))
@@ -223,6 +181,7 @@ func (self Transactions) RlpData() interface{} {
 
 	return enc
 }
+
 func (s Transactions) Len() int            { return len(s) }
 func (s Transactions) Swap(i, j int)       { s[i], s[j] = s[j], s[i] }
 func (s Transactions) GetRlp(i int) []byte { return common.Rlp(s[i]) }