diff --git a/config/toml.go b/config/toml.go
index af5be234..882d2289 100644
--- a/config/toml.go
+++ b/config/toml.go
@@ -276,8 +276,8 @@ var testGenesis = `{
   "validators": [
     {
       "pub_key": {
-        "type": "ed25519",
-        "data":"3B3069C422E19688B45CBFAE7BB009FC0FA1B1EA86593519318B7214853803C8"
+        "type": "AC26791624DE60",
+        "value":"AT/+aaL1eB0477Mud9JMm8Sh8BIvOYlPGC9KkIUmFaE="
       },
       "power": 10,
       "name": ""
@@ -289,12 +289,12 @@ var testGenesis = `{
 var testPrivValidator = `{
   "address": "D028C9981F7A87F3093672BF0D5B0E2A1B3ED456",
   "pub_key": {
-    "type": "ed25519",
-    "data": "3B3069C422E19688B45CBFAE7BB009FC0FA1B1EA86593519318B7214853803C8"
+    "type": "AC26791624DE60",
+    "value": "AT/+aaL1eB0477Mud9JMm8Sh8BIvOYlPGC9KkIUmFaE="
   },
   "priv_key": {
-    "type": "ed25519",
-    "data": "27F82582AEFAE7AB151CFB01C48BB6C1A0DA78F9BDDA979A9F70A84D074EB07D3B3069C422E19688B45CBFAE7BB009FC0FA1B1EA86593519318B7214853803C8"
+    "type": "954568A3288910",
+    "value": "EVkqJO/jIXp3rkASXfh9YnyToYXRXhBr6g9cQVxPFnQBP/5povV4HTjvsy530kybxKHwEi85iU8YL0qQhSYVoQ=="
   },
   "last_height": 0,
   "last_round": 0,
diff --git a/state/execution.go b/state/execution.go
index 64db9f31..0ce5e44f 100644
--- a/state/execution.go
+++ b/state/execution.go
@@ -245,7 +245,7 @@ func execBlockOnProxyApp(logger log.Logger, proxyAppConn proxy.AppConnConsensus,
 // ./lite/doc.go for details on how a light client tracks validators.
 func updateValidators(currentSet *types.ValidatorSet, updates []abci.Validator) error {
 	for _, v := range updates {
-		pubkey, err := crypto.PubKeyFromBytes(v.PubKey) // NOTE: expects go-wire encoded pubkey
+		pubkey, err := crypto.PubKeyFromBytes(v.PubKey) // NOTE: expects go-amino encoded pubkey
 		if err != nil {
 			return err
 		}
diff --git a/state/execution_test.go b/state/execution_test.go
index e508c0fa..09c40b5a 100644
--- a/state/execution_test.go
+++ b/state/execution_test.go
@@ -66,8 +66,8 @@ func TestBeginBlockAbsentValidators(t *testing.T) {
 		lastCommitPrecommits     []*types.Vote
 		expectedAbsentValidators []int32
 	}{
-		{"none absent", []*types.Vote{{ValidatorIndex: 0, Timestamp: now}, {ValidatorIndex: 1, Timestamp: now}}, []int32{}},
-		{"one absent", []*types.Vote{{ValidatorIndex: 0, Timestamp: now}, nil}, []int32{1}},
+		{"none absent", []*types.Vote{{ValidatorIndex: 0, Timestamp: now, Type: types.VoteTypePrecommit}, {ValidatorIndex: 1, Timestamp: now}}, []int32{}},
+		{"one absent", []*types.Vote{{ValidatorIndex: 0, Timestamp: now, Type: types.VoteTypePrecommit}, nil}, []int32{1}},
 		{"multiple absent", []*types.Vote{nil, nil}, []int32{0, 1}},
 	}
 
diff --git a/state/state.go b/state/state.go
index fb5d78c4..aa6e04b6 100644
--- a/state/state.go
+++ b/state/state.go
@@ -6,8 +6,6 @@ import (
 	"io/ioutil"
 	"time"
 
-	wire "github.com/tendermint/go-wire"
-
 	"github.com/tendermint/tendermint/types"
 )
 
@@ -81,16 +79,13 @@ func (s State) Copy() State {
 
 // Equals returns true if the States are identical.
 func (s State) Equals(s2 State) bool {
-	return bytes.Equal(s.Bytes(), s2.Bytes())
+	sbz, s2bz := s.Bytes(), s2.Bytes()
+	return bytes.Equal(sbz, s2bz)
 }
 
-// Bytes serializes the State using go-wire.
+// Bytes serializes the State using go-amino.
 func (s State) Bytes() []byte {
-	bz, err := wire.MarshalBinary(s)
-	if err != nil {
-		panic(err)
-	}
-	return bz
+	return cdc.MustMarshalBinaryBare(s)
 }
 
 // IsEmpty returns true if the State is equal to the empty State.
diff --git a/state/state_test.go b/state/state_test.go
index 02c94253..27a60524 100644
--- a/state/state_test.go
+++ b/state/state_test.go
@@ -7,11 +7,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-
 	abci "github.com/tendermint/abci/types"
-
-	crypto "github.com/tendermint/go-crypto"
-
+	"github.com/tendermint/go-crypto"
 	cmn "github.com/tendermint/tmlibs/common"
 	dbm "github.com/tendermint/tmlibs/db"
 
@@ -42,7 +39,7 @@ func TestStateCopy(t *testing.T) {
 	stateCopy := state.Copy()
 
 	assert.True(state.Equals(stateCopy),
-		cmn.Fmt(`expected state and its copy to be identical. got %v\n expected %v\n`,
+		cmn.Fmt("expected state and its copy to be identical.\ngot: %v\nexpected: %v\n",
 			stateCopy, state))
 
 	stateCopy.LastBlockHeight++
@@ -62,7 +59,7 @@ func TestStateSaveLoad(t *testing.T) {
 
 	loadedState := LoadState(stateDB)
 	assert.True(state.Equals(loadedState),
-		cmn.Fmt(`expected state and its copy to be identical. got %v\n expected %v\n`,
+		cmn.Fmt("expected state and its copy to be identical.\ngot: %v\nexpected: %v\n",
 			loadedState, state))
 }
 
@@ -78,8 +75,8 @@ func TestABCIResponsesSaveLoad1(t *testing.T) {
 	// build mock responses
 	block := makeBlock(state, 2)
 	abciResponses := NewABCIResponses(block)
-	abciResponses.DeliverTx[0] = &abci.ResponseDeliverTx{Data: []byte("foo"), Tags: []cmn.KVPair{}}
-	abciResponses.DeliverTx[1] = &abci.ResponseDeliverTx{Data: []byte("bar"), Log: "ok", Tags: []cmn.KVPair{}}
+	abciResponses.DeliverTx[0] = &abci.ResponseDeliverTx{Data: []byte("foo"), Tags: nil}
+	abciResponses.DeliverTx[1] = &abci.ResponseDeliverTx{Data: []byte("bar"), Log: "ok", Tags: nil}
 	abciResponses.EndBlock = &abci.ResponseEndBlock{ValidatorUpdates: []abci.Validator{
 		{
 			PubKey: crypto.GenPrivKeyEd25519().PubKey().Bytes(),
@@ -88,11 +85,11 @@ func TestABCIResponsesSaveLoad1(t *testing.T) {
 	}}
 
 	saveABCIResponses(stateDB, block.Height, abciResponses)
-	loadedAbciResponses, err := LoadABCIResponses(stateDB, block.Height)
+	loadedABCIResponses, err := LoadABCIResponses(stateDB, block.Height)
 	assert.Nil(err)
-	assert.Equal(abciResponses, loadedAbciResponses,
-		cmn.Fmt(`ABCIResponses don't match: Got %v, Expected %v`, loadedAbciResponses,
-			abciResponses))
+	assert.Equal(abciResponses, loadedABCIResponses,
+		cmn.Fmt("ABCIResponses don't match:\ngot:       %v\nexpected: %v\n",
+			loadedABCIResponses, abciResponses))
 }
 
 // TestResultsSaveLoad tests saving and loading abci results.
@@ -109,8 +106,8 @@ func TestABCIResponsesSaveLoad2(t *testing.T) {
 		expected types.ABCIResults
 	}{
 		0: {
-			[]*abci.ResponseDeliverTx{},
-			types.ABCIResults{},
+			nil,
+			nil,
 		},
 		1: {
 			[]*abci.ResponseDeliverTx{
@@ -129,12 +126,12 @@ func TestABCIResponsesSaveLoad2(t *testing.T) {
 					}},
 			},
 			types.ABCIResults{
-				{383, []byte{}},
+				{383, nil},
 				{0, []byte("Gotcha!")},
 			}},
 		3: {
 			nil,
-			types.ABCIResults{},
+			nil,
 		},
 	}
 
@@ -430,7 +427,7 @@ func makeHeaderPartsResponsesValPubKeyChange(state State, height int64,
 
 	block := makeBlock(state, height)
 	abciResponses := &ABCIResponses{
-		EndBlock: &abci.ResponseEndBlock{ValidatorUpdates: []abci.Validator{}},
+		EndBlock: &abci.ResponseEndBlock{ValidatorUpdates: nil},
 	}
 
 	// if the pubkey is new, remove the old and add the new
@@ -452,7 +449,7 @@ func makeHeaderPartsResponsesValPowerChange(state State, height int64,
 
 	block := makeBlock(state, height)
 	abciResponses := &ABCIResponses{
-		EndBlock: &abci.ResponseEndBlock{ValidatorUpdates: []abci.Validator{}},
+		EndBlock: &abci.ResponseEndBlock{ValidatorUpdates: nil},
 	}
 
 	// if the pubkey is new, remove the old and add the new
diff --git a/state/store.go b/state/store.go
index df07ec54..ee0619d3 100644
--- a/state/store.go
+++ b/state/store.go
@@ -4,7 +4,6 @@ import (
 	"fmt"
 
 	abci "github.com/tendermint/abci/types"
-	wire "github.com/tendermint/go-wire"
 	"github.com/tendermint/tendermint/types"
 	cmn "github.com/tendermint/tmlibs/common"
 	dbm "github.com/tendermint/tmlibs/db"
@@ -69,7 +68,7 @@ func loadState(db dbm.DB, key []byte) (state State) {
 		return state
 	}
 
-	err := wire.UnmarshalBinary(buf, &state)
+	err := cdc.UnmarshalBinaryBare(buf, &state)
 	if err != nil {
 		// DATA HAS BEEN CORRUPTED OR THE SPEC HAS CHANGED
 		cmn.Exit(cmn.Fmt(`LoadState: Data has been corrupted or its spec has changed:
@@ -104,22 +103,23 @@ type ABCIResponses struct {
 
 // NewABCIResponses returns a new ABCIResponses
 func NewABCIResponses(block *types.Block) *ABCIResponses {
+	resDeliverTxs := make([]*abci.ResponseDeliverTx, block.NumTxs)
+	if block.NumTxs == 0 {
+		// This makes Amino encoding/decoding consistent.
+		resDeliverTxs = nil
+	}
 	return &ABCIResponses{
-		DeliverTx: make([]*abci.ResponseDeliverTx, block.NumTxs),
+		DeliverTx: resDeliverTxs,
 	}
 }
 
-// Bytes serializes the ABCIResponse using go-wire
-func (a *ABCIResponses) Bytes() []byte {
-	bz, err := wire.MarshalBinary(*a)
-	if err != nil {
-		panic(err)
-	}
-	return bz
+// Bytes serializes the ABCIResponse using go-amino.
+func (arz *ABCIResponses) Bytes() []byte {
+	return cdc.MustMarshalBinaryBare(arz)
 }
 
-func (a *ABCIResponses) ResultsHash() []byte {
-	results := types.NewResults(a.DeliverTx)
+func (arz *ABCIResponses) ResultsHash() []byte {
+	results := types.NewResults(arz.DeliverTx)
 	return results.Hash()
 }
 
@@ -133,7 +133,7 @@ func LoadABCIResponses(db dbm.DB, height int64) (*ABCIResponses, error) {
 	}
 
 	abciResponses := new(ABCIResponses)
-	err := wire.UnmarshalBinary(buf, abciResponses)
+	err := cdc.UnmarshalBinaryBare(buf, abciResponses)
 	if err != nil {
 		// DATA HAS BEEN CORRUPTED OR THE SPEC HAS CHANGED
 		cmn.Exit(cmn.Fmt(`LoadABCIResponses: Data has been corrupted or its spec has
@@ -159,13 +159,9 @@ type ValidatorsInfo struct {
 	LastHeightChanged int64
 }
 
-// Bytes serializes the ValidatorsInfo using go-wire
+// Bytes serializes the ValidatorsInfo using go-amino.
 func (valInfo *ValidatorsInfo) Bytes() []byte {
-	bz, err := wire.MarshalBinary(*valInfo)
-	if err != nil {
-		panic(err)
-	}
-	return bz
+	return cdc.MustMarshalBinaryBare(valInfo)
 }
 
 // LoadValidators loads the ValidatorSet for a given height.
@@ -194,7 +190,7 @@ func loadValidatorsInfo(db dbm.DB, height int64) *ValidatorsInfo {
 	}
 
 	v := new(ValidatorsInfo)
-	err := wire.UnmarshalBinary(buf, v)
+	err := cdc.UnmarshalBinaryBare(buf, v)
 	if err != nil {
 		// DATA HAS BEEN CORRUPTED OR THE SPEC HAS CHANGED
 		cmn.Exit(cmn.Fmt(`LoadValidators: Data has been corrupted or its spec has changed:
@@ -227,13 +223,9 @@ type ConsensusParamsInfo struct {
 	LastHeightChanged int64
 }
 
-// Bytes serializes the ConsensusParamsInfo using go-wire
+// Bytes serializes the ConsensusParamsInfo using go-amino.
 func (params ConsensusParamsInfo) Bytes() []byte {
-	bz, err := wire.MarshalBinary(params)
-	if err != nil {
-		panic(err)
-	}
-	return bz
+	return cdc.MustMarshalBinaryBare(params)
 }
 
 // LoadConsensusParams loads the ConsensusParams for a given height.
@@ -263,7 +255,7 @@ func loadConsensusParamsInfo(db dbm.DB, height int64) *ConsensusParamsInfo {
 	}
 
 	paramsInfo := new(ConsensusParamsInfo)
-	err := wire.UnmarshalBinary(buf, paramsInfo)
+	err := cdc.UnmarshalBinaryBare(buf, paramsInfo)
 	if err != nil {
 		// DATA HAS BEEN CORRUPTED OR THE SPEC HAS CHANGED
 		cmn.Exit(cmn.Fmt(`LoadConsensusParams: Data has been corrupted or its spec has changed:
diff --git a/state/txindex/kv/kv.go b/state/txindex/kv/kv.go
index 24e98272..9131b24f 100644
--- a/state/txindex/kv/kv.go
+++ b/state/txindex/kv/kv.go
@@ -9,8 +9,6 @@ import (
 	"time"
 
 	"github.com/pkg/errors"
-
-	wire "github.com/tendermint/go-wire"
 	cmn "github.com/tendermint/tmlibs/common"
 	dbm "github.com/tendermint/tmlibs/db"
 	"github.com/tendermint/tmlibs/pubsub/query"
@@ -68,7 +66,7 @@ func (txi *TxIndex) Get(hash []byte) (*types.TxResult, error) {
 	}
 
 	txResult := new(types.TxResult)
-	err := wire.UnmarshalBinary(rawBytes, &txResult)
+	err := cdc.UnmarshalBinaryBare(rawBytes, &txResult)
 	if err != nil {
 		return nil, fmt.Errorf("Error reading TxResult: %v", err)
 	}
@@ -91,7 +89,7 @@ func (txi *TxIndex) AddBatch(b *txindex.Batch) error {
 		}
 
 		// index tx by hash
-		rawBytes, err := wire.MarshalBinary(result)
+		rawBytes, err := cdc.MarshalBinaryBare(result)
 		if err != nil {
 			return err
 		}
@@ -116,7 +114,7 @@ func (txi *TxIndex) Index(result *types.TxResult) error {
 	}
 
 	// index tx by hash
-	rawBytes, err := wire.MarshalBinary(result)
+	rawBytes, err := cdc.MarshalBinaryBare(result)
 	if err != nil {
 		return err
 	}
diff --git a/state/txindex/kv/kv_test.go b/state/txindex/kv/kv_test.go
index ba2830e8..c14b59ae 100644
--- a/state/txindex/kv/kv_test.go
+++ b/state/txindex/kv/kv_test.go
@@ -9,18 +9,19 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	abci "github.com/tendermint/abci/types"
-	"github.com/tendermint/tendermint/state/txindex"
-	"github.com/tendermint/tendermint/types"
 	cmn "github.com/tendermint/tmlibs/common"
 	db "github.com/tendermint/tmlibs/db"
 	"github.com/tendermint/tmlibs/pubsub/query"
+
+	"github.com/tendermint/tendermint/state/txindex"
+	"github.com/tendermint/tendermint/types"
 )
 
 func TestTxIndex(t *testing.T) {
 	indexer := NewTxIndex(db.NewMemDB())
 
 	tx := types.Tx("HELLO WORLD")
-	txResult := &types.TxResult{1, 0, tx, abci.ResponseDeliverTx{Data: []byte{0}, Code: abci.CodeTypeOK, Log: "", Tags: []cmn.KVPair{}}}
+	txResult := &types.TxResult{1, 0, tx, abci.ResponseDeliverTx{Data: []byte{0}, Code: abci.CodeTypeOK, Log: "", Tags: nil}}
 	hash := tx.Hash()
 
 	batch := txindex.NewBatch(1)
@@ -35,7 +36,7 @@ func TestTxIndex(t *testing.T) {
 	assert.Equal(t, txResult, loadedTxResult)
 
 	tx2 := types.Tx("BYE BYE WORLD")
-	txResult2 := &types.TxResult{1, 0, tx2, abci.ResponseDeliverTx{Data: []byte{0}, Code: abci.CodeTypeOK, Log: "", Tags: []cmn.KVPair{}}}
+	txResult2 := &types.TxResult{1, 0, tx2, abci.ResponseDeliverTx{Data: []byte{0}, Code: abci.CodeTypeOK, Log: "", Tags: nil}}
 	hash2 := tx2.Hash()
 
 	err = indexer.Index(txResult2)
@@ -151,7 +152,7 @@ func txResultWithTags(tags []cmn.KVPair) *types.TxResult {
 
 func benchmarkTxIndex(txsCount int, b *testing.B) {
 	tx := types.Tx("HELLO WORLD")
-	txResult := &types.TxResult{1, 0, tx, abci.ResponseDeliverTx{Data: []byte{0}, Code: abci.CodeTypeOK, Log: "", Tags: []cmn.KVPair{}}}
+	txResult := &types.TxResult{1, 0, tx, abci.ResponseDeliverTx{Data: []byte{0}, Code: abci.CodeTypeOK, Log: "", Tags: nil}}
 
 	dir, err := ioutil.TempDir("", "tx_index_db")
 	if err != nil {
diff --git a/state/txindex/kv/wire.go b/state/txindex/kv/wire.go
new file mode 100644
index 00000000..ccca7525
--- /dev/null
+++ b/state/txindex/kv/wire.go
@@ -0,0 +1,10 @@
+package kv
+
+import (
+	"github.com/tendermint/go-amino"
+)
+
+var cdc = amino.NewCodec()
+
+func init() {
+}
diff --git a/state/wire.go b/state/wire.go
new file mode 100644
index 00000000..3e8b544d
--- /dev/null
+++ b/state/wire.go
@@ -0,0 +1,12 @@
+package state
+
+import (
+	"github.com/tendermint/go-amino"
+	"github.com/tendermint/go-crypto"
+)
+
+var cdc = amino.NewCodec()
+
+func init() {
+	crypto.RegisterAmino(cdc)
+}
diff --git a/types/block.go b/types/block.go
index 9d8bb42a..44e616e6 100644
--- a/types/block.go
+++ b/types/block.go
@@ -518,13 +518,15 @@ type hasher struct {
 
 func (h hasher) Hash() []byte {
 	hasher := ripemd160.New()
-	bz, err := cdc.MarshalBinaryBare(h.item)
-	if err != nil {
-		panic(err)
-	}
-	_, err = hasher.Write(bz)
-	if err != nil {
-		panic(err)
+	if h.item != nil && !cmn.IsTypedNil(h.item) {
+		bz, err := cdc.MarshalBinaryBare(h.item)
+		if err != nil {
+			panic(err)
+		}
+		_, err = hasher.Write(bz)
+		if err != nil {
+			panic(err)
+		}
 	}
 	return hasher.Sum(nil)
 
diff --git a/types/params.go b/types/params.go
index 0626663e..2df092d6 100644
--- a/types/params.go
+++ b/types/params.go
@@ -7,7 +7,7 @@ import (
 )
 
 const (
-	maxBlockSizeBytes = 104857600 // 100MB
+	MaxBlockSizeBytes = 104857600 // 100MB
 )
 
 // ConsensusParams contains consensus critical parameters
@@ -95,9 +95,9 @@ func (params *ConsensusParams) Validate() error {
 	}
 
 	// ensure blocks aren't too big
-	if params.BlockSize.MaxBytes > maxBlockSizeBytes {
+	if params.BlockSize.MaxBytes > MaxBlockSizeBytes {
 		return cmn.NewError("BlockSize.MaxBytes is too big. %d > %d",
-			params.BlockSize.MaxBytes, maxBlockSizeBytes)
+			params.BlockSize.MaxBytes, MaxBlockSizeBytes)
 	}
 	return nil
 }