diff --git a/account/priv_account.go b/account/priv_account.go
index 23114893a..96367b356 100644
--- a/account/priv_account.go
+++ b/account/priv_account.go
@@ -34,7 +34,6 @@ func GenPrivAccountFromKey(privKeyBytes [64]byte) *PrivAccount {
 		PubKey:  pubKey,
 		PrivKey: privKey,
 	}
-
 }
 
 func (privAccount *PrivAccount) Sign(o Signable) Signature {
diff --git a/types/tx.go b/types/tx.go
index ca98367e8..a36be2295 100644
--- a/types/tx.go
+++ b/types/tx.go
@@ -91,9 +91,7 @@ func (txIn *TxInput) ValidateBasic() error {
 }
 
 func (txIn *TxInput) WriteSignBytes(w io.Writer, n *int64, err *error) {
-	binary.WriteByteSlice(txIn.Address, w, n, err)
-	binary.WriteUint64(txIn.Amount, w, n, err)
-	binary.WriteUvarint(txIn.Sequence, w, n, err)
+	binary.WriteTo([]byte(Fmt(`{"Address":"%X","Amount":%v,"Sequence":%v}`, txIn.Address, txIn.Amount, txIn.Sequence)), w, n, err)
 }
 
 func (txIn *TxInput) String() string {
@@ -118,8 +116,7 @@ func (txOut *TxOutput) ValidateBasic() error {
 }
 
 func (txOut *TxOutput) WriteSignBytes(w io.Writer, n *int64, err *error) {
-	binary.WriteByteSlice(txOut.Address, w, n, err)
-	binary.WriteUint64(txOut.Amount, w, n, err)
+	binary.WriteTo([]byte(Fmt(`{"Address":"%X","Amount":%v}`, txOut.Address, txOut.Amount)), w, n, err)
 }
 
 func (txOut *TxOutput) String() string {
@@ -134,15 +131,23 @@ type SendTx struct {
 }
 
 func (tx *SendTx) WriteSignBytes(w io.Writer, n *int64, err *error) {
-	binary.WriteString(config.App().GetString("Network"), w, n, err)
-	binary.WriteUvarint(uint(len(tx.Inputs)), w, n, err)
-	for _, in := range tx.Inputs {
+	// We hex encode the network name so we don't deal with escaping issues.
+	binary.WriteTo([]byte(Fmt(`{"Network":"%X"`, config.App().GetString("Network"))), w, n, err)
+	binary.WriteTo([]byte(Fmt(`,"Tx":[%v,{"Inputs":[`, TxTypeSend)), w, n, err)
+	for i, in := range tx.Inputs {
 		in.WriteSignBytes(w, n, err)
+		if i != len(tx.Inputs)-1 {
+			binary.WriteTo([]byte(","), w, n, err)
+		}
 	}
-	binary.WriteUvarint(uint(len(tx.Outputs)), w, n, err)
-	for _, out := range tx.Outputs {
+	binary.WriteTo([]byte(`],"Outputs":[`), w, n, err)
+	for i, out := range tx.Outputs {
 		out.WriteSignBytes(w, n, err)
+		if i != len(tx.Outputs)-1 {
+			binary.WriteTo([]byte(","), w, n, err)
+		}
 	}
+	binary.WriteTo([]byte(`]}]}`), w, n, err)
 }
 
 func (tx *SendTx) String() string {
@@ -160,12 +165,12 @@ type CallTx struct {
 }
 
 func (tx *CallTx) WriteSignBytes(w io.Writer, n *int64, err *error) {
-	binary.WriteString(config.App().GetString("Network"), w, n, err)
+	// We hex encode the network name so we don't deal with escaping issues.
+	binary.WriteTo([]byte(Fmt(`{"Network":"%X"`, config.App().GetString("Network"))), w, n, err)
+	binary.WriteTo([]byte(Fmt(`,"Tx":[%v,{"Address":"%X","Data":"%X"`, TxTypeCall, tx.Address, tx.Data)), w, n, err)
+	binary.WriteTo([]byte(Fmt(`,"Fee":%v,"GasLimit":%v,"Input":`, tx.Fee, tx.GasLimit)), w, n, err)
 	tx.Input.WriteSignBytes(w, n, err)
-	binary.WriteByteSlice(tx.Address, w, n, err)
-	binary.WriteUint64(tx.GasLimit, w, n, err)
-	binary.WriteUint64(tx.Fee, w, n, err)
-	binary.WriteByteSlice(tx.Data, w, n, err)
+	binary.WriteTo([]byte(`}]}`), w, n, err)
 }
 
 func (tx *CallTx) String() string {
@@ -181,16 +186,25 @@ type BondTx struct {
 }
 
 func (tx *BondTx) WriteSignBytes(w io.Writer, n *int64, err *error) {
-	binary.WriteString(config.App().GetString("Network"), w, n, err)
-	binary.WriteBinary(tx.PubKey, w, n, err)
-	binary.WriteUvarint(uint(len(tx.Inputs)), w, n, err)
-	for _, in := range tx.Inputs {
+	// We hex encode the network name so we don't deal with escaping issues.
+	binary.WriteTo([]byte(Fmt(`{"Network":"%X"`, config.App().GetString("Network"))), w, n, err)
+	binary.WriteTo([]byte(Fmt(`,"Tx":[%v,{"Inputs":[`, TxTypeBond)), w, n, err)
+	for i, in := range tx.Inputs {
 		in.WriteSignBytes(w, n, err)
+		if i != len(tx.Inputs)-1 {
+			binary.WriteTo([]byte(","), w, n, err)
+		}
 	}
-	binary.WriteUvarint(uint(len(tx.UnbondTo)), w, n, err)
-	for _, out := range tx.UnbondTo {
+	binary.WriteTo([]byte(Fmt(`],"PubKey":`)), w, n, err)
+	binary.WriteTo(binary.JSONBytes(tx.PubKey), w, n, err)
+	binary.WriteTo([]byte(`,"UnbondTo":[`), w, n, err)
+	for i, out := range tx.UnbondTo {
 		out.WriteSignBytes(w, n, err)
+		if i != len(tx.UnbondTo)-1 {
+			binary.WriteTo([]byte(","), w, n, err)
+		}
 	}
+	binary.WriteTo([]byte(`]}]}`), w, n, err)
 }
 
 func (tx *BondTx) String() string {
@@ -206,9 +220,9 @@ type UnbondTx struct {
 }
 
 func (tx *UnbondTx) WriteSignBytes(w io.Writer, n *int64, err *error) {
-	binary.WriteString(config.App().GetString("Network"), w, n, err)
-	binary.WriteByteSlice(tx.Address, w, n, err)
-	binary.WriteUvarint(tx.Height, w, n, err)
+	// We hex encode the network name so we don't deal with escaping issues.
+	binary.WriteTo([]byte(Fmt(`{"Network":"%X"`, config.App().GetString("Network"))), w, n, err)
+	binary.WriteTo([]byte(Fmt(`,"Tx":[%v,{"Address":"%X","Height":%v}]}`, TxTypeUnbond, tx.Address, tx.Height)), w, n, err)
 }
 
 func (tx *UnbondTx) String() string {
@@ -224,9 +238,9 @@ type RebondTx struct {
 }
 
 func (tx *RebondTx) WriteSignBytes(w io.Writer, n *int64, err *error) {
-	binary.WriteString(config.App().GetString("Network"), w, n, err)
-	binary.WriteByteSlice(tx.Address, w, n, err)
-	binary.WriteUvarint(tx.Height, w, n, err)
+	// We hex encode the network name so we don't deal with escaping issues.
+	binary.WriteTo([]byte(Fmt(`{"Network":"%X"`, config.App().GetString("Network"))), w, n, err)
+	binary.WriteTo([]byte(Fmt(`,"Tx":[%v,{"Address":"%X","Height":%v}]}`, TxTypeRebond, tx.Address, tx.Height)), w, n, err)
 }
 
 func (tx *RebondTx) String() string {
diff --git a/types/tx_test.go b/types/tx_test.go
new file mode 100644
index 000000000..aa66e3119
--- /dev/null
+++ b/types/tx_test.go
@@ -0,0 +1,121 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/tendermint/tendermint/account"
+)
+
+func TestSendTxSignable(t *testing.T) {
+	sendTx := &SendTx{
+		Inputs: []*TxInput{
+			&TxInput{
+				Address:  []byte("input1"),
+				Amount:   12345,
+				Sequence: 67890,
+			},
+			&TxInput{
+				Address:  []byte("input2"),
+				Amount:   111,
+				Sequence: 222,
+			},
+		},
+		Outputs: []*TxOutput{
+			&TxOutput{
+				Address: []byte("output1"),
+				Amount:  333,
+			},
+			&TxOutput{
+				Address: []byte("output2"),
+				Amount:  444,
+			},
+		},
+	}
+	signBytes := account.SignBytes(sendTx)
+	signStr := string(signBytes)
+	expected := `{"Network":"74656E6465726D696E745F746573746E657433","Tx":[1,{"Inputs":[{"Address":"696E70757431","Amount":12345,"Sequence":67890},{"Address":"696E70757432","Amount":111,"Sequence":222}],"Outputs":[{"Address":"6F757470757431","Amount":333},{"Address":"6F757470757432","Amount":444}]}]}`
+	if signStr != expected {
+		t.Errorf("Got unexpected sign string for SendTx")
+	}
+}
+
+func TestCallTxSignable(t *testing.T) {
+	callTx := &CallTx{
+		Input: &TxInput{
+			Address:  []byte("input1"),
+			Amount:   12345,
+			Sequence: 67890,
+		},
+		Address:  []byte("contract1"),
+		GasLimit: 111,
+		Fee:      222,
+		Data:     []byte("data1"),
+	}
+	signBytes := account.SignBytes(callTx)
+	signStr := string(signBytes)
+	expected := `{"Network":"74656E6465726D696E745F746573746E657433","Tx":[2,{"Address":"636F6E747261637431","Data":"6461746131","Fee":222,"GasLimit":111,"Input":{"Address":"696E70757431","Amount":12345,"Sequence":67890}}]}`
+	if signStr != expected {
+		t.Errorf("Got unexpected sign string for CallTx")
+	}
+}
+
+func TestBondTxSignable(t *testing.T) {
+	privAccount := account.GenPrivAccountFromKey([64]byte{})
+	bondTx := &BondTx{
+		PubKey: privAccount.PubKey.(account.PubKeyEd25519),
+		Inputs: []*TxInput{
+			&TxInput{
+				Address:  []byte("input1"),
+				Amount:   12345,
+				Sequence: 67890,
+			},
+			&TxInput{
+				Address:  []byte("input2"),
+				Amount:   111,
+				Sequence: 222,
+			},
+		},
+		UnbondTo: []*TxOutput{
+			&TxOutput{
+				Address: []byte("output1"),
+				Amount:  333,
+			},
+			&TxOutput{
+				Address: []byte("output2"),
+				Amount:  444,
+			},
+		},
+	}
+	signBytes := account.SignBytes(bondTx)
+	signStr := string(signBytes)
+	expected := `{"Network":"74656E6465726D696E745F746573746E657433","Tx":[17,{"Inputs":[{"Address":"696E70757431","Amount":12345,"Sequence":67890},{"Address":"696E70757432","Amount":111,"Sequence":222}],"PubKey":[1,"3B6A27BCCEB6A42D62A3A8D02A6F0D73653215771DE243A63AC048A18B59DA29"],"UnbondTo":[{"Address":"6F757470757431","Amount":333},{"Address":"6F757470757432","Amount":444}]}]}`
+	if signStr != expected {
+		t.Errorf("Got unexpected sign string for BondTx")
+	}
+}
+
+func TestUnbondTxSignable(t *testing.T) {
+	unbondTx := &UnbondTx{
+		Address: []byte("address1"),
+		Height:  111,
+	}
+	signBytes := account.SignBytes(unbondTx)
+	signStr := string(signBytes)
+	expected := `{"Network":"74656E6465726D696E745F746573746E657433","Tx":[18,{"Address":"6164647265737331","Height":111}]}`
+	if signStr != expected {
+		t.Errorf("Got unexpected sign string for UnbondTx")
+	}
+}
+
+func TestRebondTxSignable(t *testing.T) {
+	rebondTx := &RebondTx{
+		Address: []byte("address1"),
+		Height:  111,
+	}
+	signBytes := account.SignBytes(rebondTx)
+	signStr := string(signBytes)
+	expected := `{"Network":"74656E6465726D696E745F746573746E657433","Tx":[19,{"Address":"6164647265737331","Height":111}]}`
+	if signStr != expected {
+		t.Errorf("Got unexpected sign string for RebondTx")
+	}
+}
diff --git a/types/vote.go b/types/vote.go
index dc68012ba..e8658664c 100644
--- a/types/vote.go
+++ b/types/vote.go
@@ -47,12 +47,10 @@ const (
 )
 
 func (vote *Vote) WriteSignBytes(w io.Writer, n *int64, err *error) {
-	binary.WriteString(config.App().GetString("Network"), w, n, err)
-	binary.WriteUvarint(vote.Height, w, n, err)
-	binary.WriteUvarint(vote.Round, w, n, err)
-	binary.WriteByte(vote.Type, w, n, err)
-	binary.WriteByteSlice(vote.BlockHash, w, n, err)
-	binary.WriteBinary(vote.BlockParts, w, n, err)
+	// We hex encode the network name so we don't deal with escaping issues.
+	binary.WriteTo([]byte(Fmt(`{"Network":"%X"`, config.App().GetString("Network"))), w, n, err)
+	binary.WriteTo([]byte(Fmt(`,"Vote":{"BlockHash":"%X","BlockParts":%v`, vote.BlockHash, vote.BlockParts)), w, n, err)
+	binary.WriteTo([]byte(Fmt(`,"Height":%v,"Round":%v,"Type":%v}}`, vote.Height, vote.Round, vote.Type)), w, n, err)
 }
 
 func (vote *Vote) Copy() *Vote {