diff --git a/types/evidence_test.go b/types/evidence_test.go
index 876b68ad..84811514 100644
--- a/types/evidence_test.go
+++ b/types/evidence_test.go
@@ -22,7 +22,7 @@ func makeVote(val *PrivValidatorFS, chainID string, valIndex int, height int64,
 		Type:             byte(step),
 		BlockID:          blockID,
 	}
-	sig := val.PrivKey.Sign(SignBytes(chainID, v))
+	sig := val.PrivKey.Sign(v.SignBytes(chainID))
 	v.Signature = sig
 	return v
 
@@ -41,7 +41,7 @@ func TestEvidence(t *testing.T) {
 
 	vote1 := makeVote(val, chainID, 0, 10, 2, 1, blockID)
 	badVote := makeVote(val, chainID, 0, 10, 2, 1, blockID)
-	badVote.Signature = val2.PrivKey.Sign(SignBytes(chainID, badVote))
+	badVote.Signature = val2.PrivKey.Sign(badVote.SignBytes(chainID))
 
 	cases := []voteData{
 		{vote1, makeVote(val, chainID, 0, 10, 2, 1, blockID2), true}, // different block ids
diff --git a/types/heartbeat_test.go b/types/heartbeat_test.go
index 660ccd0f..20663616 100644
--- a/types/heartbeat_test.go
+++ b/types/heartbeat_test.go
@@ -1,7 +1,6 @@
 package types
 
 import (
-	"bytes"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -34,23 +33,18 @@ func TestHeartbeatString(t *testing.T) {
 }
 
 func TestHeartbeatWriteSignBytes(t *testing.T) {
-	var n int
-	var err error
-	buf := new(bytes.Buffer)
 
 	hb := &Heartbeat{ValidatorIndex: 1, Height: 10, Round: 1}
-	hb.WriteSignBytes("0xdeadbeef", buf, &n, &err)
-	require.Equal(t, buf.String(), `{"chain_id":"0xdeadbeef","heartbeat":{"height":10,"round":1,"sequence":0,"validator_address":"","validator_index":1}}`)
+	bz := hb.SignBytes("0xdeadbeef")
+	require.Equal(t, string(bz), `{"chain_id":"0xdeadbeef","heartbeat":{"height":10,"round":1,"sequence":0,"validator_address":"","validator_index":1}}`)
 
-	buf.Reset()
 	plainHb := &Heartbeat{}
-	plainHb.WriteSignBytes("0xdeadbeef", buf, &n, &err)
-	require.Equal(t, buf.String(), `{"chain_id":"0xdeadbeef","heartbeat":{"height":0,"round":0,"sequence":0,"validator_address":"","validator_index":0}}`)
+	bz = plainHb.SignBytes("0xdeadbeef")
+	require.Equal(t, string(bz), `{"chain_id":"0xdeadbeef","heartbeat":{"height":0,"round":0,"sequence":0,"validator_address":"","validator_index":0}}`)
 
 	require.Panics(t, func() {
-		buf.Reset()
 		var nilHb *Heartbeat
-		nilHb.WriteSignBytes("0xdeadbeef", buf, &n, &err)
-		require.Equal(t, buf.String(), "null")
+		bz := nilHb.SignBytes("0xdeadbeef")
+		require.Equal(t, string(bz), "null")
 	})
 }
diff --git a/types/priv_validator_test.go b/types/priv_validator_test.go
index 08b58273..edfcdf58 100644
--- a/types/priv_validator_test.go
+++ b/types/priv_validator_test.go
@@ -185,18 +185,19 @@ func TestDifferByTimestamp(t *testing.T) {
 		proposal := newProposal(height, round, block1)
 		err := privVal.SignProposal(chainID, proposal)
 		assert.NoError(t, err, "expected no error signing proposal")
-		signBytes := SignBytes(chainID, proposal)
+		signBytes := proposal.SignBytes(chainID)
 		sig := proposal.Signature
 		timeStamp := clipToMS(proposal.Timestamp)
 
 		// manipulate the timestamp. should get changed back
 		proposal.Timestamp = proposal.Timestamp.Add(time.Millisecond)
-		proposal.Signature = crypto.Signature{}
+		var emptySig crypto.Signature
+		proposal.Signature = emptySig
 		err = privVal.SignProposal("mychainid", proposal)
 		assert.NoError(t, err, "expected no error on signing same proposal")
 
 		assert.Equal(t, timeStamp, proposal.Timestamp)
-		assert.Equal(t, signBytes, SignBytes(chainID, proposal))
+		assert.Equal(t, signBytes, proposal.SignBytes(chainID))
 		assert.Equal(t, sig, proposal.Signature)
 	}
 
@@ -208,18 +209,19 @@ func TestDifferByTimestamp(t *testing.T) {
 		err := privVal.SignVote("mychainid", vote)
 		assert.NoError(t, err, "expected no error signing vote")
 
-		signBytes := SignBytes(chainID, vote)
+		signBytes := vote.SignBytes(chainID)
 		sig := vote.Signature
 		timeStamp := clipToMS(vote.Timestamp)
 
 		// manipulate the timestamp. should get changed back
 		vote.Timestamp = vote.Timestamp.Add(time.Millisecond)
-		vote.Signature = crypto.Signature{}
+		var emptySig crypto.Signature
+		vote.Signature = emptySig
 		err = privVal.SignVote("mychainid", vote)
 		assert.NoError(t, err, "expected no error on signing same vote")
 
 		assert.Equal(t, timeStamp, vote.Timestamp)
-		assert.Equal(t, signBytes, SignBytes(chainID, vote))
+		assert.Equal(t, signBytes, vote.SignBytes(chainID))
 		assert.Equal(t, sig, vote.Signature)
 	}
 }
diff --git a/types/proposal_test.go b/types/proposal_test.go
index 6fbfbba0..bebf37ca 100644
--- a/types/proposal_test.go
+++ b/types/proposal_test.go
@@ -26,7 +26,7 @@ func init() {
 }
 
 func TestProposalSignable(t *testing.T) {
-	signBytes := SignBytes("test_chain_id", testProposal)
+	signBytes := testProposal.SignBytes("test_chain_id")
 	signStr := string(signBytes)
 
 	expected := `{"chain_id":"test_chain_id","proposal":{"block_parts_header":{"hash":"626C6F636B7061727473","total":111},"height":12345,"pol_block_id":{},"pol_round":-1,"round":23456,"timestamp":"2018-02-11T07:09:22.765Z"}}`
@@ -48,24 +48,25 @@ func TestProposalVerifySignature(t *testing.T) {
 	pubKey := privVal.GetPubKey()
 
 	prop := NewProposal(4, 2, PartSetHeader{777, []byte("proper")}, 2, BlockID{})
-	signBytes := SignBytes("test_chain_id", prop)
+	signBytes := prop.SignBytes("test_chain_id")
 
 	// sign it
 	signature, err := privVal.Signer.Sign(signBytes)
 	require.NoError(t, err)
 
 	// verify the same proposal
-	valid := pubKey.VerifyBytes(SignBytes("test_chain_id", prop), signature)
+	valid := pubKey.VerifyBytes(prop.SignBytes("test_chain_id"), signature)
 	require.True(t, valid)
 
 	// serialize, deserialize and verify again....
 	newProp := new(Proposal)
-	bs := wire.BinaryBytes(prop)
-	err = wire.ReadBinaryBytes(bs, &newProp)
+	bs, err := wire.MarshalBinary(prop)
+	require.NoError(t, err)
+	err = wire.UnmarshalBinary(bs, &newProp)
 	require.NoError(t, err)
 
 	// verify the transmitted proposal
-	newSignBytes := SignBytes("test_chain_id", newProp)
+	newSignBytes := newProp.SignBytes("test_chain_id")
 	require.Equal(t, string(signBytes), string(newSignBytes))
 	valid = pubKey.VerifyBytes(newSignBytes, signature)
 	require.True(t, valid)
@@ -73,14 +74,14 @@ func TestProposalVerifySignature(t *testing.T) {
 
 func BenchmarkProposalWriteSignBytes(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		SignBytes("test_chain_id", testProposal)
+		testProposal.SignBytes("test_chain_id")
 	}
 }
 
 func BenchmarkProposalSign(b *testing.B) {
 	privVal := GenPrivValidatorFS("")
 	for i := 0; i < b.N; i++ {
-		_, err := privVal.Signer.Sign(SignBytes("test_chain_id", testProposal))
+		_, err := privVal.Signer.Sign(testProposal.SignBytes("test_chain_id"))
 		if err != nil {
 			b.Error(err)
 		}
@@ -88,12 +89,12 @@ func BenchmarkProposalSign(b *testing.B) {
 }
 
 func BenchmarkProposalVerifySignature(b *testing.B) {
-	signBytes := SignBytes("test_chain_id", testProposal)
+	signBytes := testProposal.SignBytes("test_chain_id")
 	privVal := GenPrivValidatorFS("")
 	signature, _ := privVal.Signer.Sign(signBytes)
 	pubKey := privVal.GetPubKey()
 
 	for i := 0; i < b.N; i++ {
-		pubKey.VerifyBytes(SignBytes("test_chain_id", testProposal), signature)
+		pubKey.VerifyBytes(testProposal.SignBytes("test_chain_id"), signature)
 	}
 }
diff --git a/types/tx_test.go b/types/tx_test.go
index dc99509d..2f51a612 100644
--- a/types/tx_test.go
+++ b/types/tx_test.go
@@ -69,8 +69,9 @@ func TestValidTxProof(t *testing.T) {
 
 			// read-write must also work
 			var p2 TxProof
-			bin := wire.BinaryBytes(proof)
-			err := wire.ReadBinaryBytes(bin, &p2)
+			bin, err := wire.MarshalBinary(proof)
+			assert.Nil(err)
+			err = wire.UnmarshalBinary(bin, &p2)
 			if assert.Nil(err, "%d: %d: %+v", h, i, err) {
 				assert.Nil(p2.Validate(root), "%d: %d", h, i)
 			}
@@ -96,7 +97,8 @@ func testTxProofUnchangable(t *testing.T) {
 
 	// make sure it is valid to start with
 	assert.Nil(proof.Validate(root))
-	bin := wire.BinaryBytes(proof)
+	bin, err := wire.MarshalBinary(proof)
+	assert.Nil(err)
 
 	// try mutating the data and make sure nothing breaks
 	for j := 0; j < 500; j++ {
@@ -110,7 +112,7 @@ func testTxProofUnchangable(t *testing.T) {
 // this make sure the proof doesn't deserialize into something valid
 func assertBadProof(t *testing.T, root []byte, bad []byte, good TxProof) {
 	var proof TxProof
-	err := wire.ReadBinaryBytes(bad, &proof)
+	err := wire.UnmarshalBinary(bad, &proof)
 	if err == nil {
 		err = proof.Validate(root)
 		if err == nil {
diff --git a/types/validator_set_test.go b/types/validator_set_test.go
index 9c751237..3a8649ef 100644
--- a/types/validator_set_test.go
+++ b/types/validator_set_test.go
@@ -16,7 +16,7 @@ import (
 func randPubKey() crypto.PubKey {
 	var pubKey [32]byte
 	copy(pubKey[:], cmn.RandBytes(32))
-	return crypto.PubKeyEd25519(pubKey).Wrap()
+	return crypto.PubKeyEd25519(pubKey)
 }
 
 func randValidator_() *Validator {
@@ -291,19 +291,17 @@ func BenchmarkValidatorSetCopy(b *testing.B) {
 }
 
 func (valSet *ValidatorSet) toBytes() []byte {
-	buf, n, err := new(bytes.Buffer), new(int), new(error)
-	wire.WriteBinary(valSet, buf, n, err)
-	if *err != nil {
-		cmn.PanicCrisis(*err)
+	bz, err := wire.MarshalBinary(valSet)
+	if err != nil {
+		panic(err)
 	}
-	return buf.Bytes()
+	return bz
 }
 
 func (valSet *ValidatorSet) fromBytes(b []byte) {
-	r, n, err := bytes.NewReader(b), new(int), new(error)
-	wire.ReadBinary(valSet, r, 0, n, err)
-	if *err != nil {
+	err := wire.UnmarshalBinary(b, valSet)
+	if err != nil {
 		// DATA HAS BEEN CORRUPTED OR THE SPEC HAS CHANGED
-		cmn.PanicCrisis(*err)
+		panic(err)
 	}
 }
diff --git a/types/vote_test.go b/types/vote_test.go
index 5e2d5c0d..1da1ec7f 100644
--- a/types/vote_test.go
+++ b/types/vote_test.go
@@ -42,7 +42,7 @@ func exampleVote(t byte) *Vote {
 
 func TestVoteSignable(t *testing.T) {
 	vote := examplePrecommit()
-	signBytes := SignBytes("test_chain_id", vote)
+	signBytes := vote.SignBytes("test_chain_id")
 	signStr := string(signBytes)
 
 	expected := `{"chain_id":"test_chain_id","vote":{"block_id":{"hash":"68617368","parts":{"hash":"70617274735F68617368","total":1000000}},"height":12345,"round":2,"timestamp":"2017-12-25T03:00:01.234Z","type":2}}`
@@ -77,24 +77,25 @@ func TestVoteVerifySignature(t *testing.T) {
 	pubKey := privVal.GetPubKey()
 
 	vote := examplePrecommit()
-	signBytes := SignBytes("test_chain_id", vote)
+	signBytes := vote.SignBytes("test_chain_id")
 
 	// sign it
 	signature, err := privVal.Signer.Sign(signBytes)
 	require.NoError(t, err)
 
 	// verify the same vote
-	valid := pubKey.VerifyBytes(SignBytes("test_chain_id", vote), signature)
+	valid := pubKey.VerifyBytes(vote.SignBytes("test_chain_id"), signature)
 	require.True(t, valid)
 
 	// serialize, deserialize and verify again....
 	precommit := new(Vote)
-	bs := wire.BinaryBytes(vote)
-	err = wire.ReadBinaryBytes(bs, &precommit)
+	bs, err := wire.MarshalBinary(vote)
+	require.NoError(t, err)
+	err = wire.UnmarshalBinary(bs, &precommit)
 	require.NoError(t, err)
 
 	// verify the transmitted vote
-	newSignBytes := SignBytes("test_chain_id", precommit)
+	newSignBytes := precommit.SignBytes("test_chain_id")
 	require.Equal(t, string(signBytes), string(newSignBytes))
 	valid = pubKey.VerifyBytes(newSignBytes, signature)
 	require.True(t, valid)