diff --git a/accounts/account_manager.go b/accounts/account_manager.go
index e9eb8f8165..6cbd23c4e9 100644
--- a/accounts/account_manager.go
+++ b/accounts/account_manager.go
@@ -33,7 +33,6 @@ and accounts persistence is derived from stored keys' addresses
 package accounts
 
 import (
-	"bytes"
 	"crypto/ecdsa"
 	crand "crypto/rand"
 	"errors"
@@ -41,6 +40,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 )
 
@@ -50,12 +50,12 @@ var (
 )
 
 type Account struct {
-	Address []byte
+	Address common.Address
 }
 
 type Manager struct {
 	keyStore crypto.KeyStore2
-	unlocked map[string]*unlocked
+	unlocked map[common.Address]*unlocked
 	mutex    sync.RWMutex
 }
 
@@ -67,40 +67,40 @@ type unlocked struct {
 func NewManager(keyStore crypto.KeyStore2) *Manager {
 	return &Manager{
 		keyStore: keyStore,
-		unlocked: make(map[string]*unlocked),
+		unlocked: make(map[common.Address]*unlocked),
 	}
 }
 
-func (am *Manager) HasAccount(addr []byte) bool {
+func (am *Manager) HasAccount(addr common.Address) bool {
 	accounts, _ := am.Accounts()
 	for _, acct := range accounts {
-		if bytes.Compare(acct.Address, addr) == 0 {
+		if acct.Address == addr {
 			return true
 		}
 	}
 	return false
 }
 
-func (am *Manager) Primary() (addr []byte, err error) {
+func (am *Manager) Primary() (addr common.Address, err error) {
 	addrs, err := am.keyStore.GetKeyAddresses()
 	if os.IsNotExist(err) {
-		return nil, ErrNoKeys
+		return common.Address{}, ErrNoKeys
 	} else if err != nil {
-		return nil, err
+		return common.Address{}, err
 	}
 	if len(addrs) == 0 {
-		return nil, ErrNoKeys
+		return common.Address{}, ErrNoKeys
 	}
 	return addrs[0], nil
 }
 
-func (am *Manager) DeleteAccount(address []byte, auth string) error {
+func (am *Manager) DeleteAccount(address common.Address, auth string) error {
 	return am.keyStore.DeleteKey(address, auth)
 }
 
 func (am *Manager) Sign(a Account, toSign []byte) (signature []byte, err error) {
 	am.mutex.RLock()
-	unlockedKey, found := am.unlocked[string(a.Address)]
+	unlockedKey, found := am.unlocked[a.Address]
 	am.mutex.RUnlock()
 	if !found {
 		return nil, ErrLocked
@@ -111,7 +111,7 @@ func (am *Manager) Sign(a Account, toSign []byte) (signature []byte, err error)
 
 // TimedUnlock unlocks the account with the given address.
 // When timeout has passed, the account will be locked again.
-func (am *Manager) TimedUnlock(addr []byte, keyAuth string, timeout time.Duration) error {
+func (am *Manager) TimedUnlock(addr common.Address, keyAuth string, timeout time.Duration) error {
 	key, err := am.keyStore.GetKey(addr, keyAuth)
 	if err != nil {
 		return err
@@ -124,7 +124,7 @@ func (am *Manager) TimedUnlock(addr []byte, keyAuth string, timeout time.Duratio
 // Unlock unlocks the account with the given address. The account
 // stays unlocked until the program exits or until a TimedUnlock
 // timeout (started after the call to Unlock) expires.
-func (am *Manager) Unlock(addr []byte, keyAuth string) error {
+func (am *Manager) Unlock(addr common.Address, keyAuth string) error {
 	key, err := am.keyStore.GetKey(addr, keyAuth)
 	if err != nil {
 		return err
@@ -157,10 +157,10 @@ func (am *Manager) Accounts() ([]Account, error) {
 	return accounts, err
 }
 
-func (am *Manager) addUnlocked(addr []byte, key *crypto.Key) *unlocked {
+func (am *Manager) addUnlocked(addr common.Address, key *crypto.Key) *unlocked {
 	u := &unlocked{Key: key, abort: make(chan struct{})}
 	am.mutex.Lock()
-	prev, found := am.unlocked[string(addr)]
+	prev, found := am.unlocked[addr]
 	if found {
 		// terminate dropLater for this key to avoid unexpected drops.
 		close(prev.abort)
@@ -169,12 +169,12 @@ func (am *Manager) addUnlocked(addr []byte, key *crypto.Key) *unlocked {
 		// key, i.e. when Unlock was used.
 		zeroKey(prev.PrivateKey)
 	}
-	am.unlocked[string(addr)] = u
+	am.unlocked[addr] = u
 	am.mutex.Unlock()
 	return u
 }
 
-func (am *Manager) dropLater(addr []byte, u *unlocked, timeout time.Duration) {
+func (am *Manager) dropLater(addr common.Address, u *unlocked, timeout time.Duration) {
 	t := time.NewTimer(timeout)
 	defer t.Stop()
 	select {
@@ -186,9 +186,9 @@ func (am *Manager) dropLater(addr []byte, u *unlocked, timeout time.Duration) {
 		// was launched with. we can check that using pointer equality
 		// because the map stores a new pointer every time the key is
 		// unlocked.
-		if am.unlocked[string(addr)] == u {
+		if am.unlocked[addr] == u {
 			zeroKey(u.PrivateKey)
-			delete(am.unlocked, string(addr))
+			delete(am.unlocked, addr)
 		}
 		am.mutex.Unlock()
 	}
@@ -204,7 +204,7 @@ func zeroKey(k *ecdsa.PrivateKey) {
 
 // USE WITH CAUTION = this will save an unencrypted private key on disk
 // no cli or js interface
-func (am *Manager) Export(path string, addr []byte, keyAuth string) error {
+func (am *Manager) Export(path string, addr common.Address, keyAuth string) error {
 	key, err := am.keyStore.GetKey(addr, keyAuth)
 	if err != nil {
 		return err
diff --git a/cmd/geth/admin.go b/cmd/geth/admin.go
index b0cb7507ac..949a7bde08 100644
--- a/cmd/geth/admin.go
+++ b/cmd/geth/admin.go
@@ -391,7 +391,7 @@ func (js *jsre) unlock(call otto.FunctionCall) otto.Value {
 		}
 	}
 	am := js.ethereum.AccountManager()
-	err = am.TimedUnlock(common.FromHex(addr), passphrase, time.Duration(seconds)*time.Second)
+	err = am.TimedUnlock(common.HexToAddress(addr), passphrase, time.Duration(seconds)*time.Second)
 	if err != nil {
 		fmt.Printf("Unlock account failed '%v'\n", err)
 		return otto.FalseValue()
@@ -433,7 +433,7 @@ func (js *jsre) newAccount(call otto.FunctionCall) otto.Value {
 		fmt.Printf("Could not create the account: %v", err)
 		return otto.UndefinedValue()
 	}
-	return js.re.ToVal(common.ToHex(acct.Address))
+	return js.re.ToVal(acct.Address.Hex())
 }
 
 func (js *jsre) nodeInfo(call otto.FunctionCall) otto.Value {
diff --git a/cmd/geth/js.go b/cmd/geth/js.go
index 61e97433a9..4ddb3bd9ca 100644
--- a/cmd/geth/js.go
+++ b/cmd/geth/js.go
@@ -26,6 +26,7 @@ import (
 	"strings"
 
 	"github.com/ethereum/go-ethereum/cmd/utils"
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/docserver"
 	"github.com/ethereum/go-ethereum/common/natspec"
 	"github.com/ethereum/go-ethereum/eth"
@@ -164,7 +165,7 @@ func (self *jsre) UnlockAccount(addr []byte) bool {
 		return false
 	}
 	// TODO: allow retry
-	if err := self.ethereum.AccountManager().Unlock(addr, pass); err != nil {
+	if err := self.ethereum.AccountManager().Unlock(common.BytesToAddress(addr), pass); err != nil {
 		return false
 	} else {
 		fmt.Println("Account is now unlocked for this session.")
diff --git a/cmd/geth/main.go b/cmd/geth/main.go
index 5fe83a2a0d..dbcfe81758 100644
--- a/cmd/geth/main.go
+++ b/cmd/geth/main.go
@@ -365,11 +365,10 @@ func unlockAccount(ctx *cli.Context, am *accounts.Manager, account string) (pass
 	// Load startup keys. XXX we are going to need a different format
 	// Attempt to unlock the account
 	passphrase = getPassPhrase(ctx, "", false)
-	accbytes := common.FromHex(account)
-	if len(accbytes) == 0 {
+	if len(account) == 0 {
 		utils.Fatalf("Invalid account address '%s'", account)
 	}
-	err = am.Unlock(accbytes, passphrase)
+	err = am.Unlock(common.StringToAddress(account), passphrase)
 	if err != nil {
 		utils.Fatalf("Unlock account failed '%v'", err)
 	}
@@ -385,11 +384,11 @@ func startEth(ctx *cli.Context, eth *eth.Ethereum) {
 	account := ctx.GlobalString(utils.UnlockedAccountFlag.Name)
 	if len(account) > 0 {
 		if account == "primary" {
-			accbytes, err := am.Primary()
+			primaryAcc, err := am.Primary()
 			if err != nil {
 				utils.Fatalf("no primary account: %v", err)
 			}
-			account = common.ToHex(accbytes)
+			account = primaryAcc.Hex()
 		}
 		unlockAccount(ctx, am, account)
 	}
diff --git a/cmd/mist/gui.go b/cmd/mist/gui.go
index 53194ae50a..f443bacbcc 100644
--- a/cmd/mist/gui.go
+++ b/cmd/mist/gui.go
@@ -232,7 +232,7 @@ func (self *Gui) loadMergedMiningOptions() {
 func (gui *Gui) insertTransaction(window string, tx *types.Transaction) {
 	var inout string
 	from, _ := tx.From()
-	if gui.eth.AccountManager().HasAccount(common.Hex2Bytes(from.Hex())) {
+	if gui.eth.AccountManager().HasAccount(from) {
 		inout = "send"
 	} else {
 		inout = "recv"
diff --git a/crypto/crypto.go b/crypto/crypto.go
index 6fc5bfd363..2b1628124e 100644
--- a/crypto/crypto.go
+++ b/crypto/crypto.go
@@ -231,13 +231,13 @@ func decryptPreSaleKey(fileContent []byte, password string) (key *Key, err error
 	ecKey := ToECDSA(ethPriv)
 	key = &Key{
 		Id:         nil,
-		Address:    PubkeyToAddress(ecKey.PublicKey),
+		Address:    common.BytesToAddress(PubkeyToAddress(ecKey.PublicKey)),
 		PrivateKey: ecKey,
 	}
-	derivedAddr := common.Bytes2Hex(key.Address)
+	derivedAddr := hex.EncodeToString(key.Address.Bytes()) // needed because .Hex() gives leading "0x"
 	expectedAddr := preSaleKeyStruct.EthAddr
 	if derivedAddr != expectedAddr {
-		err = errors.New("decrypted addr not equal to expected addr")
+		err = errors.New(fmt.Sprintf("decrypted addr not equal to expected addr ", derivedAddr, expectedAddr))
 	}
 	return key, err
 }
diff --git a/crypto/key.go b/crypto/key.go
index 654d9e83da..5e1f3637ea 100644
--- a/crypto/key.go
+++ b/crypto/key.go
@@ -30,12 +30,13 @@ import (
 	"io"
 
 	"code.google.com/p/go-uuid/uuid"
+	"github.com/ethereum/go-ethereum/common"
 )
 
 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 []byte
+	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
@@ -63,7 +64,7 @@ type encryptedKeyJSON struct {
 func (k *Key) MarshalJSON() (j []byte, err error) {
 	jStruct := plainKeyJSON{
 		k.Id,
-		k.Address,
+		k.Address.Bytes(),
 		FromECDSA(k.PrivateKey),
 	}
 	j, err = json.Marshal(jStruct)
@@ -80,7 +81,7 @@ func (k *Key) UnmarshalJSON(j []byte) (err error) {
 	u := new(uuid.UUID)
 	*u = keyJSON.Id
 	k.Id = *u
-	k.Address = keyJSON.Address
+	k.Address = common.BytesToAddress(keyJSON.Address)
 	k.PrivateKey = ToECDSA(keyJSON.PrivateKey)
 
 	return err
@@ -90,7 +91,7 @@ func NewKeyFromECDSA(privateKeyECDSA *ecdsa.PrivateKey) *Key {
 	id := uuid.NewRandom()
 	key := &Key{
 		Id:         id,
-		Address:    PubkeyToAddress(privateKeyECDSA.PublicKey),
+		Address:    common.BytesToAddress(PubkeyToAddress(privateKeyECDSA.PublicKey)),
 		PrivateKey: privateKeyECDSA,
 	}
 	return key
diff --git a/crypto/key_store_passphrase.go b/crypto/key_store_passphrase.go
index 4cfb1851b3..739483d9fd 100644
--- a/crypto/key_store_passphrase.go
+++ b/crypto/key_store_passphrase.go
@@ -68,7 +68,6 @@ import (
 	"bytes"
 	"crypto/aes"
 	"crypto/cipher"
-	"encoding/hex"
 	"encoding/json"
 	"errors"
 	"io"
@@ -76,6 +75,7 @@ import (
 	"path/filepath"
 
 	"code.google.com/p/go-uuid/uuid"
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto/randentropy"
 	"golang.org/x/crypto/scrypt"
 )
@@ -100,7 +100,7 @@ func (ks keyStorePassphrase) GenerateNewKey(rand io.Reader, auth string) (key *K
 	return GenerateNewKeyDefault(ks, rand, auth)
 }
 
-func (ks keyStorePassphrase) GetKey(keyAddr []byte, auth string) (key *Key, err error) {
+func (ks keyStorePassphrase) GetKey(keyAddr common.Address, auth string) (key *Key, err error) {
 	keyBytes, keyId, err := DecryptKey(ks, keyAddr, auth)
 	if err != nil {
 		return nil, err
@@ -113,7 +113,7 @@ func (ks keyStorePassphrase) GetKey(keyAddr []byte, auth string) (key *Key, err
 	return key, err
 }
 
-func (ks keyStorePassphrase) GetKeyAddresses() (addresses [][]byte, err error) {
+func (ks keyStorePassphrase) GetKeyAddresses() (addresses []common.Address, err error) {
 	return GetKeyAddresses(ks.keysDirPath)
 }
 
@@ -150,7 +150,7 @@ func (ks keyStorePassphrase) StoreKey(key *Key, auth string) (err error) {
 	}
 	keyStruct := encryptedKeyJSON{
 		key.Id,
-		key.Address,
+		key.Address.Bytes(),
 		cipherStruct,
 	}
 	keyJSON, err := json.Marshal(keyStruct)
@@ -161,18 +161,18 @@ func (ks keyStorePassphrase) StoreKey(key *Key, auth string) (err error) {
 	return WriteKeyFile(key.Address, ks.keysDirPath, keyJSON)
 }
 
-func (ks keyStorePassphrase) DeleteKey(keyAddr []byte, auth string) (err error) {
+func (ks keyStorePassphrase) DeleteKey(keyAddr common.Address, auth string) (err error) {
 	// only delete if correct passphrase is given
 	_, _, err = DecryptKey(ks, keyAddr, auth)
 	if err != nil {
 		return err
 	}
 
-	keyDirPath := filepath.Join(ks.keysDirPath, hex.EncodeToString(keyAddr))
+	keyDirPath := filepath.Join(ks.keysDirPath, keyAddr.Hex())
 	return os.RemoveAll(keyDirPath)
 }
 
-func DecryptKey(ks keyStorePassphrase, keyAddr []byte, auth string) (keyBytes []byte, keyId []byte, err error) {
+func DecryptKey(ks keyStorePassphrase, keyAddr common.Address, auth string) (keyBytes []byte, keyId []byte, err error) {
 	fileContent, err := GetKeyFile(ks.keysDirPath, keyAddr)
 	if err != nil {
 		return nil, nil, err
diff --git a/crypto/key_store_plain.go b/crypto/key_store_plain.go
index 581968d7c9..2ade119852 100644
--- a/crypto/key_store_plain.go
+++ b/crypto/key_store_plain.go
@@ -27,6 +27,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
+	"github.com/ethereum/go-ethereum/common"
 	"io"
 	"io/ioutil"
 	"os"
@@ -37,10 +38,10 @@ import (
 type KeyStore2 interface {
 	// create new key using io.Reader entropy source and optionally using auth string
 	GenerateNewKey(io.Reader, string) (*Key, error)
-	GetKey([]byte, string) (*Key, error) // key from addr and auth string
-	GetKeyAddresses() ([][]byte, error)  // get all addresses
-	StoreKey(*Key, string) error         // store key optionally using auth string
-	DeleteKey([]byte, string) error      // delete key by addr and auth string
+	GetKey(common.Address, string) (*Key, error) // key from addr and auth string
+	GetKeyAddresses() ([]common.Address, error)  // get all addresses
+	StoreKey(*Key, string) error                 // store key optionally using auth string
+	DeleteKey(common.Address, string) error      // delete key by addr and auth string
 }
 
 type keyStorePlain struct {
@@ -66,7 +67,7 @@ func GenerateNewKeyDefault(ks KeyStore2, rand io.Reader, auth string) (key *Key,
 	return key, err
 }
 
-func (ks keyStorePlain) GetKey(keyAddr []byte, auth string) (key *Key, err error) {
+func (ks keyStorePlain) GetKey(keyAddr common.Address, auth string) (key *Key, err error) {
 	fileContent, err := GetKeyFile(ks.keysDirPath, keyAddr)
 	if err != nil {
 		return nil, err
@@ -77,7 +78,7 @@ func (ks keyStorePlain) GetKey(keyAddr []byte, auth string) (key *Key, err error
 	return key, err
 }
 
-func (ks keyStorePlain) GetKeyAddresses() (addresses [][]byte, err error) {
+func (ks keyStorePlain) GetKeyAddresses() (addresses []common.Address, err error) {
 	return GetKeyAddresses(ks.keysDirPath)
 }
 
@@ -90,19 +91,19 @@ func (ks keyStorePlain) StoreKey(key *Key, auth string) (err error) {
 	return err
 }
 
-func (ks keyStorePlain) DeleteKey(keyAddr []byte, auth string) (err error) {
-	keyDirPath := filepath.Join(ks.keysDirPath, hex.EncodeToString(keyAddr))
+func (ks keyStorePlain) DeleteKey(keyAddr common.Address, auth string) (err error) {
+	keyDirPath := filepath.Join(ks.keysDirPath, keyAddr.Hex())
 	err = os.RemoveAll(keyDirPath)
 	return err
 }
 
-func GetKeyFile(keysDirPath string, keyAddr []byte) (fileContent []byte, err error) {
-	fileName := hex.EncodeToString(keyAddr)
+func GetKeyFile(keysDirPath string, keyAddr common.Address) (fileContent []byte, err error) {
+	fileName := keyAddr.Hex()
 	return ioutil.ReadFile(filepath.Join(keysDirPath, fileName, fileName))
 }
 
-func WriteKeyFile(addr []byte, keysDirPath string, content []byte) (err error) {
-	addrHex := hex.EncodeToString(addr)
+func WriteKeyFile(addr common.Address, keysDirPath string, content []byte) (err error) {
+	addrHex := addr.Hex()
 	keyDirPath := filepath.Join(keysDirPath, addrHex)
 	keyFilePath := filepath.Join(keyDirPath, addrHex)
 	err = os.MkdirAll(keyDirPath, 0700) // read, write and dir search for user
@@ -112,7 +113,7 @@ func WriteKeyFile(addr []byte, keysDirPath string, content []byte) (err error) {
 	return ioutil.WriteFile(keyFilePath, content, 0600) // read, write for user
 }
 
-func GetKeyAddresses(keysDirPath string) (addresses [][]byte, err error) {
+func GetKeyAddresses(keysDirPath string) (addresses []common.Address, err error) {
 	fileInfos, err := ioutil.ReadDir(keysDirPath)
 	if err != nil {
 		return nil, err
@@ -122,7 +123,7 @@ func GetKeyAddresses(keysDirPath string) (addresses [][]byte, err error) {
 		if err != nil {
 			continue
 		}
-		addresses = append(addresses, address)
+		addresses = append(addresses, common.BytesToAddress(address))
 	}
 	return addresses, err
 }
diff --git a/eth/backend.go b/eth/backend.go
index 7960a0e61d..65b096d49c 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -386,14 +386,17 @@ func (s *Ethereum) StartMining(threads int) error {
 func (s *Ethereum) Etherbase() (eb common.Address, err error) {
 	eb = s.etherbase
 	if (eb == common.Address{}) {
-		var ebbytes []byte
-		ebbytes, err = s.accountManager.Primary()
-		eb = common.BytesToAddress(ebbytes)
-		if (eb == common.Address{}) {
-			err = fmt.Errorf("no accounts found")
+		primary, err := s.accountManager.Primary()
+		if err != nil {
+			return eb, err
 		}
+		if (primary == common.Address{}) {
+			err = fmt.Errorf("no accounts found")
+			return eb, err
+		}
+		eb = primary
 	}
-	return
+	return eb, nil
 }
 
 func (s *Ethereum) StopMining()         { s.miner.Stop() }
diff --git a/xeth/xeth.go b/xeth/xeth.go
index 11dc506b85..74110c4ec1 100644
--- a/xeth/xeth.go
+++ b/xeth/xeth.go
@@ -365,7 +365,7 @@ func (self *XEth) Accounts() []string {
 	accounts, _ := self.backend.AccountManager().Accounts()
 	accountAddresses := make([]string, len(accounts))
 	for i, ac := range accounts {
-		accountAddresses[i] = common.ToHex(ac.Address)
+		accountAddresses[i] = ac.Address.Str()
 	}
 	return accountAddresses
 }