diff --git a/CHANGELOG_PENDING.md b/CHANGELOG_PENDING.md
index d0e555d96..0b7711e47 100644
--- a/CHANGELOG_PENDING.md
+++ b/CHANGELOG_PENDING.md
@@ -12,6 +12,7 @@ Friendly reminder, we have a [bug bounty program](https://hackerone.com/tendermi
 
   - [evidence] \#4725 Remove `Pubkey` from DuplicateVoteEvidence
   - [rpc] [\#4792](https://github.com/tendermint/tendermint/pull/4792) `/validators` are now sorted by voting power (@melekes)
+  - [blockchain] \#4637 Transition blockchain reactor(s) to Protobuf encoding
   - [types] \#4382  `SignedMsgType` has moved to a Protobuf enum types
   - [types] \#4382 `Total` has been changed from a `int` to a `uint32`
   - [types] \#4582 Vote: `ValidatorIndex` & `Round` are now int32
diff --git a/blockchain/msgs.go b/blockchain/msgs.go
new file mode 100644
index 000000000..dfcf95e3d
--- /dev/null
+++ b/blockchain/msgs.go
@@ -0,0 +1,118 @@
+package blockchain
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/gogo/protobuf/proto"
+
+	bcproto "github.com/tendermint/tendermint/proto/blockchain"
+	"github.com/tendermint/tendermint/types"
+)
+
+const (
+	// NOTE: keep up to date with bcproto.BlockResponse
+	BlockResponseMessagePrefixSize   = 4
+	BlockResponseMessageFieldKeySize = 1
+	MaxMsgSize                       = types.MaxBlockSizeBytes +
+		BlockResponseMessagePrefixSize +
+		BlockResponseMessageFieldKeySize
+)
+
+// EncodeMsg encodes a Protobuf message
+func EncodeMsg(pb proto.Message) ([]byte, error) {
+	msg := bcproto.Message{}
+
+	switch pb := pb.(type) {
+	case *bcproto.BlockRequest:
+		msg.Sum = &bcproto.Message_BlockRequest{BlockRequest: pb}
+	case *bcproto.BlockResponse:
+		msg.Sum = &bcproto.Message_BlockResponse{BlockResponse: pb}
+	case *bcproto.NoBlockResponse:
+		msg.Sum = &bcproto.Message_NoBlockResponse{NoBlockResponse: pb}
+	case *bcproto.StatusRequest:
+		msg.Sum = &bcproto.Message_StatusRequest{StatusRequest: pb}
+	case *bcproto.StatusResponse:
+		msg.Sum = &bcproto.Message_StatusResponse{StatusResponse: pb}
+	default:
+		return nil, fmt.Errorf("unknown message type %T", pb)
+	}
+
+	bz, err := proto.Marshal(&msg)
+	if err != nil {
+		return nil, fmt.Errorf("unable to marshal %T: %w", pb, err)
+	}
+
+	return bz, nil
+}
+
+// DecodeMsg decodes a Protobuf message.
+func DecodeMsg(bz []byte) (proto.Message, error) {
+	pb := &bcproto.Message{}
+
+	err := proto.Unmarshal(bz, pb)
+	if err != nil {
+		return nil, err
+	}
+
+	switch msg := pb.Sum.(type) {
+	case *bcproto.Message_BlockRequest:
+		return msg.BlockRequest, nil
+	case *bcproto.Message_BlockResponse:
+		return msg.BlockResponse, nil
+	case *bcproto.Message_NoBlockResponse:
+		return msg.NoBlockResponse, nil
+	case *bcproto.Message_StatusRequest:
+		return msg.StatusRequest, nil
+	case *bcproto.Message_StatusResponse:
+		return msg.StatusResponse, nil
+	default:
+		return nil, fmt.Errorf("unknown message type %T", msg)
+	}
+}
+
+// ValidateMsg validates a message.
+func ValidateMsg(pb proto.Message) error {
+	if pb == nil {
+		return errors.New("message cannot be nil")
+	}
+
+	switch msg := pb.(type) {
+	case *bcproto.BlockRequest:
+		if msg.Height < 0 {
+			return errors.New("negative Height")
+		}
+	case *bcproto.BlockResponse:
+		_, err := types.BlockFromProto(msg.Block)
+		if err != nil {
+			return err
+		}
+	case *bcproto.NoBlockResponse:
+		if msg.Height < 0 {
+			return errors.New("negative Height")
+		}
+	case *bcproto.StatusResponse:
+		if msg.Base < 0 {
+			return errors.New("negative Base")
+		}
+		if msg.Height < 0 {
+			return errors.New("negative Height")
+		}
+		if msg.Base > msg.Height {
+			return fmt.Errorf("base %v cannot be greater than height %v", msg.Base, msg.Height)
+		}
+	case *bcproto.StatusRequest:
+		if msg.Base < 0 {
+			return errors.New("negative Base")
+		}
+		if msg.Height < 0 {
+			return errors.New("negative Height")
+		}
+		if msg.Base > msg.Height {
+			return fmt.Errorf("base %v cannot be greater than height %v", msg.Base, msg.Height)
+		}
+	default:
+		return fmt.Errorf("unknown message type %T", msg)
+	}
+	return nil
+}
diff --git a/blockchain/msgs_test.go b/blockchain/msgs_test.go
new file mode 100644
index 000000000..7d1ff41f3
--- /dev/null
+++ b/blockchain/msgs_test.go
@@ -0,0 +1,88 @@
+package blockchain
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	bcproto "github.com/tendermint/tendermint/proto/blockchain"
+)
+
+func TestBcBlockRequestMessageValidateBasic(t *testing.T) {
+	testCases := []struct {
+		testName      string
+		requestHeight int64
+		expectErr     bool
+	}{
+		{"Valid Request Message", 0, false},
+		{"Valid Request Message", 1, false},
+		{"Invalid Request Message", -1, true},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.testName, func(t *testing.T) {
+			request := bcproto.BlockRequest{Height: tc.requestHeight}
+			assert.Equal(t, tc.expectErr, ValidateMsg(&request) != nil, "Validate Basic had an unexpected result")
+		})
+	}
+}
+
+func TestBcNoBlockResponseMessageValidateBasic(t *testing.T) {
+	testCases := []struct {
+		testName          string
+		nonResponseHeight int64
+		expectErr         bool
+	}{
+		{"Valid Non-Response Message", 0, false},
+		{"Valid Non-Response Message", 1, false},
+		{"Invalid Non-Response Message", -1, true},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.testName, func(t *testing.T) {
+			nonResponse := bcproto.NoBlockResponse{Height: tc.nonResponseHeight}
+			assert.Equal(t, tc.expectErr, ValidateMsg(&nonResponse) != nil, "Validate Basic had an unexpected result")
+		})
+	}
+}
+
+func TestBcStatusRequestMessageValidateBasic(t *testing.T) {
+	testCases := []struct {
+		testName      string
+		requestHeight int64
+		expectErr     bool
+	}{
+		{"Valid Request Message", 0, false},
+		{"Valid Request Message", 1, false},
+		{"Invalid Request Message", -1, true},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.testName, func(t *testing.T) {
+			request := bcproto.StatusRequest{Height: tc.requestHeight}
+			assert.Equal(t, tc.expectErr, ValidateMsg(&request) != nil, "Validate Basic had an unexpected result")
+		})
+	}
+}
+
+func TestBcStatusResponseMessageValidateBasic(t *testing.T) {
+	testCases := []struct {
+		testName       string
+		responseHeight int64
+		expectErr      bool
+	}{
+		{"Valid Response Message", 0, false},
+		{"Valid Response Message", 1, false},
+		{"Invalid Response Message", -1, true},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.testName, func(t *testing.T) {
+			response := bcproto.StatusResponse{Height: tc.responseHeight}
+			assert.Equal(t, tc.expectErr, ValidateMsg(&response) != nil, "Validate Basic had an unexpected result")
+		})
+	}
+}
diff --git a/blockchain/v0/codec.go b/blockchain/v0/codec.go
deleted file mode 100644
index f023bbfa1..000000000
--- a/blockchain/v0/codec.go
+++ /dev/null
@@ -1,14 +0,0 @@
-package v0
-
-import (
-	amino "github.com/tendermint/go-amino"
-
-	"github.com/tendermint/tendermint/types"
-)
-
-var cdc = amino.NewCodec()
-
-func init() {
-	RegisterBlockchainMessages(cdc)
-	types.RegisterBlockAmino(cdc)
-}
diff --git a/blockchain/v0/reactor.go b/blockchain/v0/reactor.go
index 1adde6bd5..8d809c2c0 100644
--- a/blockchain/v0/reactor.go
+++ b/blockchain/v0/reactor.go
@@ -1,15 +1,14 @@
 package v0
 
 import (
-	"errors"
 	"fmt"
 	"reflect"
 	"time"
 
-	amino "github.com/tendermint/go-amino"
-
+	bc "github.com/tendermint/tendermint/blockchain"
 	"github.com/tendermint/tendermint/libs/log"
 	"github.com/tendermint/tendermint/p2p"
+	bcproto "github.com/tendermint/tendermint/proto/blockchain"
 	sm "github.com/tendermint/tendermint/state"
 	"github.com/tendermint/tendermint/store"
 	"github.com/tendermint/tendermint/types"
@@ -29,13 +28,6 @@ const (
 	statusUpdateIntervalSeconds = 10
 	// check if we should switch to consensus reactor
 	switchToConsensusIntervalSeconds = 1
-
-	// NOTE: keep up to date with bcBlockResponseMessage
-	bcBlockResponseMessagePrefixSize   = 4
-	bcBlockResponseMessageFieldKeySize = 1
-	maxMsgSize                         = types.MaxBlockSizeBytes +
-		bcBlockResponseMessagePrefixSize +
-		bcBlockResponseMessageFieldKeySize
 )
 
 type consensusReactor interface {
@@ -147,17 +139,21 @@ func (bcR *BlockchainReactor) GetChannels() []*p2p.ChannelDescriptor {
 			Priority:            10,
 			SendQueueCapacity:   1000,
 			RecvBufferCapacity:  50 * 4096,
-			RecvMessageCapacity: maxMsgSize,
+			RecvMessageCapacity: bc.MaxMsgSize,
 		},
 	}
 }
 
 // AddPeer implements Reactor by sending our state to peer.
 func (bcR *BlockchainReactor) AddPeer(peer p2p.Peer) {
-	msgBytes := cdc.MustMarshalBinaryBare(&bcStatusResponseMessage{
-		Height: bcR.store.Height(),
+	msgBytes, err := bc.EncodeMsg(&bcproto.StatusResponse{
 		Base:   bcR.store.Base(),
-	})
+		Height: bcR.store.Height()})
+	if err != nil {
+		bcR.Logger.Error("could not convert msg to protobuf", "err", err)
+		return
+	}
+
 	peer.Send(BlockchainChannel, msgBytes)
 	// it's OK if send fails. will try later in poolRoutine
 
@@ -172,31 +168,47 @@ func (bcR *BlockchainReactor) RemovePeer(peer p2p.Peer, reason interface{}) {
 
 // respondToPeer loads a block and sends it to the requesting peer,
 // if we have it. Otherwise, we'll respond saying we don't have it.
-func (bcR *BlockchainReactor) respondToPeer(msg *bcBlockRequestMessage,
+func (bcR *BlockchainReactor) respondToPeer(msg *bcproto.BlockRequest,
 	src p2p.Peer) (queued bool) {
 
 	block := bcR.store.LoadBlock(msg.Height)
 	if block != nil {
-		msgBytes := cdc.MustMarshalBinaryBare(&bcBlockResponseMessage{Block: block})
+		bl, err := block.ToProto()
+		if err != nil {
+			bcR.Logger.Error("could not convert msg to protobuf", "err", err)
+			return false
+		}
+
+		msgBytes, err := bc.EncodeMsg(&bcproto.BlockResponse{Block: bl})
+		if err != nil {
+			bcR.Logger.Error("could not marshal msg", "err", err)
+			return false
+		}
+
 		return src.TrySend(BlockchainChannel, msgBytes)
 	}
 
 	bcR.Logger.Info("Peer asking for a block we don't have", "src", src, "height", msg.Height)
 
-	msgBytes := cdc.MustMarshalBinaryBare(&bcNoBlockResponseMessage{Height: msg.Height})
+	msgBytes, err := bc.EncodeMsg(&bcproto.NoBlockResponse{Height: msg.Height})
+	if err != nil {
+		bcR.Logger.Error("could not convert msg to protobuf", "err", err)
+		return false
+	}
+
 	return src.TrySend(BlockchainChannel, msgBytes)
 }
 
 // Receive implements Reactor by handling 4 types of messages (look below).
 func (bcR *BlockchainReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte) {
-	msg, err := decodeMsg(msgBytes)
+	msg, err := bc.DecodeMsg(msgBytes)
 	if err != nil {
 		bcR.Logger.Error("Error decoding message", "src", src, "chId", chID, "msg", msg, "err", err, "bytes", msgBytes)
 		bcR.Switch.StopPeerForError(src, err)
 		return
 	}
 
-	if err = msg.ValidateBasic(); err != nil {
+	if err = bc.ValidateMsg(msg); err != nil {
 		bcR.Logger.Error("Peer sent us invalid msg", "peer", src, "msg", msg, "err", err)
 		bcR.Switch.StopPeerForError(src, err)
 		return
@@ -205,20 +217,30 @@ func (bcR *BlockchainReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte)
 	bcR.Logger.Debug("Receive", "src", src, "chID", chID, "msg", msg)
 
 	switch msg := msg.(type) {
-	case *bcBlockRequestMessage:
+	case *bcproto.BlockRequest:
 		bcR.respondToPeer(msg, src)
-	case *bcBlockResponseMessage:
-		bcR.pool.AddBlock(src.ID(), msg.Block, len(msgBytes))
-	case *bcStatusRequestMessage:
+	case *bcproto.BlockResponse:
+		bi, err := types.BlockFromProto(msg.Block)
+		if err != nil {
+			bcR.Logger.Error("Block content is invalid", "err", err)
+			return
+		}
+		bcR.pool.AddBlock(src.ID(), bi, len(msgBytes))
+	case *bcproto.StatusRequest:
 		// Send peer our state.
-		src.TrySend(BlockchainChannel, cdc.MustMarshalBinaryBare(&bcStatusResponseMessage{
+		msgBytes, err := bc.EncodeMsg(&bcproto.StatusResponse{
 			Height: bcR.store.Height(),
 			Base:   bcR.store.Base(),
-		}))
-	case *bcStatusResponseMessage:
+		})
+		if err != nil {
+			bcR.Logger.Error("could not convert msg to protobut", "err", err)
+			return
+		}
+		src.TrySend(BlockchainChannel, msgBytes)
+	case *bcproto.StatusResponse:
 		// Got a peer status. Unverified.
 		bcR.pool.SetPeerRange(src.ID(), msg.Base, msg.Height)
-	case *bcNoBlockResponseMessage:
+	case *bcproto.NoBlockResponse:
 		bcR.Logger.Debug("Peer does not have requested block", "peer", src, "height", msg.Height)
 	default:
 		bcR.Logger.Error(fmt.Sprintf("Unknown message type %v", reflect.TypeOf(msg)))
@@ -255,7 +277,12 @@ func (bcR *BlockchainReactor) poolRoutine(stateSynced bool) {
 				if peer == nil {
 					continue
 				}
-				msgBytes := cdc.MustMarshalBinaryBare(&bcBlockRequestMessage{request.Height})
+				msgBytes, err := bc.EncodeMsg(&bcproto.BlockRequest{Height: request.Height})
+				if err != nil {
+					bcR.Logger.Error("could not convert msg to proto", "err", err)
+					continue
+				}
+
 				queued := peer.TrySend(BlockchainChannel, msgBytes)
 				if !queued {
 					bcR.Logger.Debug("Send queue is full, drop block request", "peer", peer.ID(), "height", request.Height)
@@ -381,132 +408,16 @@ FOR_LOOP:
 
 // BroadcastStatusRequest broadcasts `BlockStore` base and height.
 func (bcR *BlockchainReactor) BroadcastStatusRequest() error {
-	msgBytes := cdc.MustMarshalBinaryBare(&bcStatusRequestMessage{
+	bm, err := bc.EncodeMsg(&bcproto.StatusRequest{
 		Base:   bcR.store.Base(),
 		Height: bcR.store.Height(),
 	})
-	bcR.Switch.Broadcast(BlockchainChannel, msgBytes)
-	return nil
-}
-
-//-----------------------------------------------------------------------------
-// Messages
-
-// BlockchainMessage is a generic message for this reactor.
-type BlockchainMessage interface {
-	ValidateBasic() error
-}
-
-// RegisterBlockchainMessages registers the fast sync messages for amino encoding.
-func RegisterBlockchainMessages(cdc *amino.Codec) {
-	cdc.RegisterInterface((*BlockchainMessage)(nil), nil)
-	cdc.RegisterConcrete(&bcBlockRequestMessage{}, "tendermint/blockchain/BlockRequest", nil)
-	cdc.RegisterConcrete(&bcBlockResponseMessage{}, "tendermint/blockchain/BlockResponse", nil)
-	cdc.RegisterConcrete(&bcNoBlockResponseMessage{}, "tendermint/blockchain/NoBlockResponse", nil)
-	cdc.RegisterConcrete(&bcStatusResponseMessage{}, "tendermint/blockchain/StatusResponse", nil)
-	cdc.RegisterConcrete(&bcStatusRequestMessage{}, "tendermint/blockchain/StatusRequest", nil)
-}
-
-func decodeMsg(bz []byte) (msg BlockchainMessage, err error) {
-	err = cdc.UnmarshalBinaryBare(bz, &msg)
-	return
-}
-
-//-------------------------------------
-
-type bcBlockRequestMessage struct {
-	Height int64
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcBlockRequestMessage) ValidateBasic() error {
-	if m.Height < 0 {
-		return errors.New("negative Height")
-	}
-	return nil
-}
-
-func (m *bcBlockRequestMessage) String() string {
-	return fmt.Sprintf("[bcBlockRequestMessage %v]", m.Height)
-}
-
-type bcNoBlockResponseMessage struct {
-	Height int64
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcNoBlockResponseMessage) ValidateBasic() error {
-	if m.Height < 0 {
-		return errors.New("negative Height")
-	}
-	return nil
-}
-
-func (m *bcNoBlockResponseMessage) String() string {
-	return fmt.Sprintf("[bcNoBlockResponseMessage %d]", m.Height)
-}
-
-//-------------------------------------
-
-type bcBlockResponseMessage struct {
-	Block *types.Block
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcBlockResponseMessage) ValidateBasic() error {
-	return m.Block.ValidateBasic()
-}
-
-func (m *bcBlockResponseMessage) String() string {
-	return fmt.Sprintf("[bcBlockResponseMessage %v]", m.Block.Height)
-}
-
-//-------------------------------------
-
-type bcStatusRequestMessage struct {
-	Height int64
-	Base   int64
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcStatusRequestMessage) ValidateBasic() error {
-	if m.Base < 0 {
-		return errors.New("negative Base")
-	}
-	if m.Height < 0 {
-		return errors.New("negative Height")
-	}
-	if m.Base > m.Height {
-		return fmt.Errorf("base %v cannot be greater than height %v", m.Base, m.Height)
+	if err != nil {
+		bcR.Logger.Error("could not convert msg to proto", "err", err)
+		return fmt.Errorf("could not convert msg to proto: %w", err)
 	}
-	return nil
-}
 
-func (m *bcStatusRequestMessage) String() string {
-	return fmt.Sprintf("[bcStatusRequestMessage %v:%v]", m.Base, m.Height)
-}
-
-//-------------------------------------
+	bcR.Switch.Broadcast(BlockchainChannel, bm)
 
-type bcStatusResponseMessage struct {
-	Height int64
-	Base   int64
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcStatusResponseMessage) ValidateBasic() error {
-	if m.Base < 0 {
-		return errors.New("negative Base")
-	}
-	if m.Height < 0 {
-		return errors.New("negative Height")
-	}
-	if m.Base > m.Height {
-		return fmt.Errorf("base %v cannot be greater than height %v", m.Base, m.Height)
-	}
 	return nil
 }
-
-func (m *bcStatusResponseMessage) String() string {
-	return fmt.Sprintf("[bcStatusResponseMessage %v:%v]", m.Base, m.Height)
-}
diff --git a/blockchain/v0/reactor_test.go b/blockchain/v0/reactor_test.go
index 5acf01431..f8c231544 100644
--- a/blockchain/v0/reactor_test.go
+++ b/blockchain/v0/reactor_test.go
@@ -263,86 +263,6 @@ func TestBadBlockStopsPeer(t *testing.T) {
 	assert.True(t, lastReactorPair.reactor.Switch.Peers().Size() < len(reactorPairs)-1)
 }
 
-func TestBcBlockRequestMessageValidateBasic(t *testing.T) {
-	testCases := []struct {
-		testName      string
-		requestHeight int64
-		expectErr     bool
-	}{
-		{"Valid Request Message", 0, false},
-		{"Valid Request Message", 1, false},
-		{"Invalid Request Message", -1, true},
-	}
-
-	for _, tc := range testCases {
-		tc := tc
-		t.Run(tc.testName, func(t *testing.T) {
-			request := bcBlockRequestMessage{Height: tc.requestHeight}
-			assert.Equal(t, tc.expectErr, request.ValidateBasic() != nil, "Validate Basic had an unexpected result")
-		})
-	}
-}
-
-func TestBcNoBlockResponseMessageValidateBasic(t *testing.T) {
-	testCases := []struct {
-		testName          string
-		nonResponseHeight int64
-		expectErr         bool
-	}{
-		{"Valid Non-Response Message", 0, false},
-		{"Valid Non-Response Message", 1, false},
-		{"Invalid Non-Response Message", -1, true},
-	}
-
-	for _, tc := range testCases {
-		tc := tc
-		t.Run(tc.testName, func(t *testing.T) {
-			nonResponse := bcNoBlockResponseMessage{Height: tc.nonResponseHeight}
-			assert.Equal(t, tc.expectErr, nonResponse.ValidateBasic() != nil, "Validate Basic had an unexpected result")
-		})
-	}
-}
-
-func TestBcStatusRequestMessageValidateBasic(t *testing.T) {
-	testCases := []struct {
-		testName      string
-		requestHeight int64
-		expectErr     bool
-	}{
-		{"Valid Request Message", 0, false},
-		{"Valid Request Message", 1, false},
-		{"Invalid Request Message", -1, true},
-	}
-
-	for _, tc := range testCases {
-		tc := tc
-		t.Run(tc.testName, func(t *testing.T) {
-			request := bcStatusRequestMessage{Height: tc.requestHeight}
-			assert.Equal(t, tc.expectErr, request.ValidateBasic() != nil, "Validate Basic had an unexpected result")
-		})
-	}
-}
-
-func TestBcStatusResponseMessageValidateBasic(t *testing.T) {
-	testCases := []struct {
-		testName       string
-		responseHeight int64
-		expectErr      bool
-	}{
-		{"Valid Response Message", 0, false},
-		{"Valid Response Message", 1, false},
-		{"Invalid Response Message", -1, true},
-	}
-
-	for _, tc := range testCases {
-		tc := tc
-		t.Run(tc.testName, func(t *testing.T) {
-			response := bcStatusResponseMessage{Height: tc.responseHeight}
-			assert.Equal(t, tc.expectErr, response.ValidateBasic() != nil, "Validate Basic had an unexpected result")
-		})
-	}
-}
-
 //----------------------------------------------
 // utility funcs
 
diff --git a/blockchain/v1/codec.go b/blockchain/v1/codec.go
deleted file mode 100644
index ce4f7dfab..000000000
--- a/blockchain/v1/codec.go
+++ /dev/null
@@ -1,14 +0,0 @@
-package v1
-
-import (
-	amino "github.com/tendermint/go-amino"
-
-	"github.com/tendermint/tendermint/types"
-)
-
-var cdc = amino.NewCodec()
-
-func init() {
-	RegisterBlockchainMessages(cdc)
-	types.RegisterBlockAmino(cdc)
-}
diff --git a/blockchain/v1/reactor.go b/blockchain/v1/reactor.go
index 970825d14..3a61916e4 100644
--- a/blockchain/v1/reactor.go
+++ b/blockchain/v1/reactor.go
@@ -1,16 +1,15 @@
 package v1
 
 import (
-	"errors"
 	"fmt"
 	"reflect"
 	"time"
 
-	amino "github.com/tendermint/go-amino"
-
 	"github.com/tendermint/tendermint/behaviour"
+	bc "github.com/tendermint/tendermint/blockchain"
 	"github.com/tendermint/tendermint/libs/log"
 	"github.com/tendermint/tendermint/p2p"
+	bcproto "github.com/tendermint/tendermint/proto/blockchain"
 	sm "github.com/tendermint/tendermint/state"
 	"github.com/tendermint/tendermint/store"
 	"github.com/tendermint/tendermint/types"
@@ -24,13 +23,6 @@ const (
 
 	// ask for best height every 10s
 	statusUpdateIntervalSeconds = 10
-
-	// NOTE: keep up to date with bcBlockResponseMessage
-	bcBlockResponseMessagePrefixSize   = 4
-	bcBlockResponseMessageFieldKeySize = 1
-	maxMsgSize                         = types.MaxBlockSizeBytes +
-		bcBlockResponseMessagePrefixSize +
-		bcBlockResponseMessageFieldKeySize
 )
 
 var (
@@ -176,17 +168,21 @@ func (bcR *BlockchainReactor) GetChannels() []*p2p.ChannelDescriptor {
 			Priority:            10,
 			SendQueueCapacity:   2000,
 			RecvBufferCapacity:  50 * 4096,
-			RecvMessageCapacity: maxMsgSize,
+			RecvMessageCapacity: bc.MaxMsgSize,
 		},
 	}
 }
 
 // AddPeer implements Reactor by sending our state to peer.
 func (bcR *BlockchainReactor) AddPeer(peer p2p.Peer) {
-	msgBytes := cdc.MustMarshalBinaryBare(&bcStatusResponseMessage{
+	msgBytes, err := bc.EncodeMsg(&bcproto.StatusResponse{
 		Base:   bcR.store.Base(),
 		Height: bcR.store.Height(),
 	})
+	if err != nil {
+		bcR.Logger.Error("could not convert msg to protobuf", "err", err)
+		return
+	}
 	peer.Send(BlockchainChannel, msgBytes)
 	// it's OK if send fails. will try later in poolRoutine
 
@@ -197,26 +193,44 @@ func (bcR *BlockchainReactor) AddPeer(peer p2p.Peer) {
 // sendBlockToPeer loads a block and sends it to the requesting peer.
 // If the block doesn't exist a bcNoBlockResponseMessage is sent.
 // If all nodes are honest, no node should be requesting for a block that doesn't exist.
-func (bcR *BlockchainReactor) sendBlockToPeer(msg *bcBlockRequestMessage,
+func (bcR *BlockchainReactor) sendBlockToPeer(msg *bcproto.BlockRequest,
 	src p2p.Peer) (queued bool) {
 
 	block := bcR.store.LoadBlock(msg.Height)
 	if block != nil {
-		msgBytes := cdc.MustMarshalBinaryBare(&bcBlockResponseMessage{Block: block})
+		pbbi, err := block.ToProto()
+		if err != nil {
+			bcR.Logger.Error("Could not send block message to peer", "err", err)
+			return false
+		}
+		msgBytes, err := bc.EncodeMsg(&bcproto.BlockResponse{Block: pbbi})
+		if err != nil {
+			bcR.Logger.Error("unable to marshal msg", "err", err)
+			return false
+		}
 		return src.TrySend(BlockchainChannel, msgBytes)
 	}
 
 	bcR.Logger.Info("peer asking for a block we don't have", "src", src, "height", msg.Height)
 
-	msgBytes := cdc.MustMarshalBinaryBare(&bcNoBlockResponseMessage{Height: msg.Height})
+	msgBytes, err := bc.EncodeMsg(&bcproto.NoBlockResponse{Height: msg.Height})
+	if err != nil {
+		bcR.Logger.Error("unable to marshal msg", "err", err)
+		return false
+	}
 	return src.TrySend(BlockchainChannel, msgBytes)
 }
 
-func (bcR *BlockchainReactor) sendStatusResponseToPeer(msg *bcStatusRequestMessage, src p2p.Peer) (queued bool) {
-	msgBytes := cdc.MustMarshalBinaryBare(&bcStatusResponseMessage{
+func (bcR *BlockchainReactor) sendStatusResponseToPeer(msg *bcproto.StatusRequest, src p2p.Peer) (queued bool) {
+	msgBytes, err := bc.EncodeMsg(&bcproto.StatusResponse{
 		Base:   bcR.store.Base(),
 		Height: bcR.store.Height(),
 	})
+	if err != nil {
+		bcR.Logger.Error("unable to marshal msg", "err", err)
+		return false
+	}
+
 	return src.TrySend(BlockchainChannel, msgBytes)
 }
 
@@ -234,7 +248,7 @@ func (bcR *BlockchainReactor) RemovePeer(peer p2p.Peer, reason interface{}) {
 
 // Receive implements Reactor by handling 4 types of messages (look below).
 func (bcR *BlockchainReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte) {
-	msg, err := decodeMsg(msgBytes)
+	msg, err := bc.DecodeMsg(msgBytes)
 	if err != nil {
 		bcR.Logger.Error("error decoding message",
 			"src", src, "chId", chID, "msg", msg, "err", err, "bytes", msgBytes)
@@ -242,7 +256,7 @@ func (bcR *BlockchainReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte)
 		return
 	}
 
-	if err = msg.ValidateBasic(); err != nil {
+	if err = bc.ValidateMsg(msg); err != nil {
 		bcR.Logger.Error("peer sent us invalid msg", "peer", src, "msg", msg, "err", err)
 		_ = bcR.swReporter.Report(behaviour.BadMessage(src.ID(), err.Error()))
 		return
@@ -251,33 +265,38 @@ func (bcR *BlockchainReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte)
 	bcR.Logger.Debug("Receive", "src", src, "chID", chID, "msg", msg)
 
 	switch msg := msg.(type) {
-	case *bcBlockRequestMessage:
+	case *bcproto.BlockRequest:
 		if queued := bcR.sendBlockToPeer(msg, src); !queued {
 			// Unfortunately not queued since the queue is full.
 			bcR.Logger.Error("Could not send block message to peer", "src", src, "height", msg.Height)
 		}
 
-	case *bcStatusRequestMessage:
+	case *bcproto.StatusRequest:
 		// Send peer our state.
 		if queued := bcR.sendStatusResponseToPeer(msg, src); !queued {
 			// Unfortunately not queued since the queue is full.
 			bcR.Logger.Error("Could not send status message to peer", "src", src)
 		}
 
-	case *bcBlockResponseMessage:
+	case *bcproto.BlockResponse:
+		bi, err := types.BlockFromProto(msg.Block)
+		if err != nil {
+			bcR.Logger.Error("error transition block from protobuf", "err", err)
+			return
+		}
 		msgForFSM := bcReactorMessage{
 			event: blockResponseEv,
 			data: bReactorEventData{
 				peerID: src.ID(),
-				height: msg.Block.Height,
-				block:  msg.Block,
+				height: bi.Height,
+				block:  bi,
 				length: len(msgBytes),
 			},
 		}
-		bcR.Logger.Info("Received", "src", src, "height", msg.Block.Height)
+		bcR.Logger.Info("Received", "src", src, "height", bi.Height)
 		bcR.messagesForFSMCh <- msgForFSM
 
-	case *bcStatusResponseMessage:
+	case *bcproto.StatusResponse:
 		// Got a peer status. Unverified.
 		msgForFSM := bcReactorMessage{
 			event: statusResponseEv,
@@ -461,10 +480,13 @@ func (bcR *BlockchainReactor) processBlock() error {
 // Implements bcRNotifier
 // sendStatusRequest broadcasts `BlockStore` height.
 func (bcR *BlockchainReactor) sendStatusRequest() {
-	msgBytes := cdc.MustMarshalBinaryBare(&bcStatusRequestMessage{
+	msgBytes, err := bc.EncodeMsg(&bcproto.StatusRequest{
 		Base:   bcR.store.Base(),
 		Height: bcR.store.Height(),
 	})
+	if err != nil {
+		panic(err)
+	}
 	bcR.Switch.Broadcast(BlockchainChannel, msgBytes)
 }
 
@@ -476,7 +498,10 @@ func (bcR *BlockchainReactor) sendBlockRequest(peerID p2p.ID, height int64) erro
 		return errNilPeerForBlockRequest
 	}
 
-	msgBytes := cdc.MustMarshalBinaryBare(&bcBlockRequestMessage{height})
+	msgBytes, err := bc.EncodeMsg(&bcproto.BlockRequest{Height: height})
+	if err != nil {
+		return err
+	}
 	queued := peer.TrySend(BlockchainChannel, msgBytes)
 	if !queued {
 		return errSendQueueFull
@@ -533,125 +558,3 @@ func (bcR *BlockchainReactor) resetStateTimer(name string, timer **time.Timer, t
 		(*timer).Reset(timeout)
 	}
 }
-
-//-----------------------------------------------------------------------------
-// Messages
-
-// BlockchainMessage is a generic message for this reactor.
-type BlockchainMessage interface {
-	ValidateBasic() error
-}
-
-// RegisterBlockchainMessages registers the fast sync messages for amino encoding.
-func RegisterBlockchainMessages(cdc *amino.Codec) {
-	cdc.RegisterInterface((*BlockchainMessage)(nil), nil)
-	cdc.RegisterConcrete(&bcBlockRequestMessage{}, "tendermint/blockchain/BlockRequest", nil)
-	cdc.RegisterConcrete(&bcBlockResponseMessage{}, "tendermint/blockchain/BlockResponse", nil)
-	cdc.RegisterConcrete(&bcNoBlockResponseMessage{}, "tendermint/blockchain/NoBlockResponse", nil)
-	cdc.RegisterConcrete(&bcStatusResponseMessage{}, "tendermint/blockchain/StatusResponse", nil)
-	cdc.RegisterConcrete(&bcStatusRequestMessage{}, "tendermint/blockchain/StatusRequest", nil)
-}
-
-func decodeMsg(bz []byte) (msg BlockchainMessage, err error) {
-	err = cdc.UnmarshalBinaryBare(bz, &msg)
-	return
-}
-
-//-------------------------------------
-
-type bcBlockRequestMessage struct {
-	Height int64
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcBlockRequestMessage) ValidateBasic() error {
-	if m.Height < 0 {
-		return errors.New("negative Height")
-	}
-	return nil
-}
-
-func (m *bcBlockRequestMessage) String() string {
-	return fmt.Sprintf("[bcBlockRequestMessage %v]", m.Height)
-}
-
-type bcNoBlockResponseMessage struct {
-	Height int64
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcNoBlockResponseMessage) ValidateBasic() error {
-	if m.Height < 0 {
-		return errors.New("negative Height")
-	}
-	return nil
-}
-
-func (m *bcNoBlockResponseMessage) String() string {
-	return fmt.Sprintf("[bcNoBlockResponseMessage %d]", m.Height)
-}
-
-//-------------------------------------
-
-type bcBlockResponseMessage struct {
-	Block *types.Block
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcBlockResponseMessage) ValidateBasic() error {
-	return m.Block.ValidateBasic()
-}
-
-func (m *bcBlockResponseMessage) String() string {
-	return fmt.Sprintf("[bcBlockResponseMessage %v]", m.Block.Height)
-}
-
-//-------------------------------------
-
-type bcStatusRequestMessage struct {
-	Height int64
-	Base   int64
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcStatusRequestMessage) ValidateBasic() error {
-	if m.Height < 0 {
-		return errors.New("negative Height")
-	}
-	if m.Base < 0 {
-		return errors.New("negative Base")
-	}
-	if m.Base > m.Height {
-		return fmt.Errorf("base %v cannot be greater than height %v", m.Base, m.Height)
-	}
-	return nil
-}
-
-func (m *bcStatusRequestMessage) String() string {
-	return fmt.Sprintf("[bcStatusRequestMessage %v:%v]", m.Base, m.Height)
-}
-
-//-------------------------------------
-
-type bcStatusResponseMessage struct {
-	Height int64
-	Base   int64
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcStatusResponseMessage) ValidateBasic() error {
-	if m.Height < 0 {
-		return errors.New("negative Height")
-	}
-	if m.Base < 0 {
-		return errors.New("negative Base")
-	}
-	if m.Base > m.Height {
-		return fmt.Errorf("base %v cannot be greater than height %v", m.Base, m.Height)
-	}
-	return nil
-}
-
-func (m *bcStatusResponseMessage) String() string {
-	return fmt.Sprintf("[bcStatusResponseMessage %v:%v]", m.Base, m.Height)
-}
diff --git a/blockchain/v1/reactor_test.go b/blockchain/v1/reactor_test.go
index 0d71e0be5..b7e337e1d 100644
--- a/blockchain/v1/reactor_test.go
+++ b/blockchain/v1/reactor_test.go
@@ -338,86 +338,6 @@ outerFor:
 	assert.True(t, lastReactorPair.bcR.Switch.Peers().Size() < len(reactorPairs)-1)
 }
 
-func TestBcBlockRequestMessageValidateBasic(t *testing.T) {
-	testCases := []struct {
-		testName      string
-		requestHeight int64
-		expectErr     bool
-	}{
-		{"Valid Request Message", 0, false},
-		{"Valid Request Message", 1, false},
-		{"Invalid Request Message", -1, true},
-	}
-
-	for _, tc := range testCases {
-		tc := tc
-		t.Run(tc.testName, func(t *testing.T) {
-			request := bcBlockRequestMessage{Height: tc.requestHeight}
-			assert.Equal(t, tc.expectErr, request.ValidateBasic() != nil, "Validate Basic had an unexpected result")
-		})
-	}
-}
-
-func TestBcNoBlockResponseMessageValidateBasic(t *testing.T) {
-	testCases := []struct {
-		testName          string
-		nonResponseHeight int64
-		expectErr         bool
-	}{
-		{"Valid Non-Response Message", 0, false},
-		{"Valid Non-Response Message", 1, false},
-		{"Invalid Non-Response Message", -1, true},
-	}
-
-	for _, tc := range testCases {
-		tc := tc
-		t.Run(tc.testName, func(t *testing.T) {
-			nonResponse := bcNoBlockResponseMessage{Height: tc.nonResponseHeight}
-			assert.Equal(t, tc.expectErr, nonResponse.ValidateBasic() != nil, "Validate Basic had an unexpected result")
-		})
-	}
-}
-
-func TestBcStatusRequestMessageValidateBasic(t *testing.T) {
-	testCases := []struct {
-		testName      string
-		requestHeight int64
-		expectErr     bool
-	}{
-		{"Valid Request Message", 0, false},
-		{"Valid Request Message", 1, false},
-		{"Invalid Request Message", -1, true},
-	}
-
-	for _, tc := range testCases {
-		tc := tc
-		t.Run(tc.testName, func(t *testing.T) {
-			request := bcStatusRequestMessage{Height: tc.requestHeight}
-			assert.Equal(t, tc.expectErr, request.ValidateBasic() != nil, "Validate Basic had an unexpected result")
-		})
-	}
-}
-
-func TestBcStatusResponseMessageValidateBasic(t *testing.T) {
-	testCases := []struct {
-		testName       string
-		responseHeight int64
-		expectErr      bool
-	}{
-		{"Valid Response Message", 0, false},
-		{"Valid Response Message", 1, false},
-		{"Invalid Response Message", -1, true},
-	}
-
-	for _, tc := range testCases {
-		tc := tc
-		t.Run(tc.testName, func(t *testing.T) {
-			response := bcStatusResponseMessage{Height: tc.responseHeight}
-			assert.Equal(t, tc.expectErr, response.ValidateBasic() != nil, "Validate Basic had an unexpected result")
-		})
-	}
-}
-
 //----------------------------------------------
 // utility funcs
 
diff --git a/blockchain/v2/codec.go b/blockchain/v2/codec.go
deleted file mode 100644
index 4e92846c4..000000000
--- a/blockchain/v2/codec.go
+++ /dev/null
@@ -1,14 +0,0 @@
-package v2
-
-import (
-	amino "github.com/tendermint/go-amino"
-
-	"github.com/tendermint/tendermint/types"
-)
-
-var cdc = amino.NewCodec()
-
-func init() {
-	RegisterBlockchainMessages(cdc)
-	types.RegisterBlockAmino(cdc)
-}
diff --git a/blockchain/v2/io.go b/blockchain/v2/io.go
index 54e8c1518..27de3b8af 100644
--- a/blockchain/v2/io.go
+++ b/blockchain/v2/io.go
@@ -3,7 +3,9 @@ package v2
 import (
 	"fmt"
 
+	bc "github.com/tendermint/tendermint/blockchain"
 	"github.com/tendermint/tendermint/p2p"
+	bcproto "github.com/tendermint/tendermint/proto/blockchain"
 	"github.com/tendermint/tendermint/state"
 	"github.com/tendermint/tendermint/types"
 )
@@ -14,7 +16,7 @@ type iIO interface {
 	sendBlockNotFound(height int64, peerID p2p.ID) error
 	sendStatusResponse(base int64, height int64, peerID p2p.ID) error
 
-	broadcastStatusRequest(base int64, height int64)
+	broadcastStatusRequest(base int64, height int64) error
 
 	trySwitchToConsensus(state state.State, skipWAL bool) bool
 }
@@ -45,8 +47,11 @@ func (sio *switchIO) sendBlockRequest(peerID p2p.ID, height int64) error {
 	if peer == nil {
 		return fmt.Errorf("peer not found")
 	}
+	msgBytes, err := bc.EncodeMsg(&bcproto.BlockRequest{Height: height})
+	if err != nil {
+		return err
+	}
 
-	msgBytes := cdc.MustMarshalBinaryBare(&bcBlockRequestMessage{Height: height})
 	queued := peer.TrySend(BlockchainChannel, msgBytes)
 	if !queued {
 		return fmt.Errorf("send queue full")
@@ -59,7 +64,11 @@ func (sio *switchIO) sendStatusResponse(base int64, height int64, peerID p2p.ID)
 	if peer == nil {
 		return fmt.Errorf("peer not found")
 	}
-	msgBytes := cdc.MustMarshalBinaryBare(&bcStatusResponseMessage{Base: base, Height: height})
+
+	msgBytes, err := bc.EncodeMsg(&bcproto.StatusResponse{Height: height, Base: base})
+	if err != nil {
+		return err
+	}
 
 	if queued := peer.TrySend(BlockchainChannel, msgBytes); !queued {
 		return fmt.Errorf("peer queue full")
@@ -76,7 +85,16 @@ func (sio *switchIO) sendBlockToPeer(block *types.Block, peerID p2p.ID) error {
 	if block == nil {
 		panic("trying to send nil block")
 	}
-	msgBytes := cdc.MustMarshalBinaryBare(&bcBlockResponseMessage{Block: block})
+
+	bpb, err := block.ToProto()
+	if err != nil {
+		return err
+	}
+
+	msgBytes, err := bc.EncodeMsg(&bcproto.BlockResponse{Block: bpb})
+	if err != nil {
+		return err
+	}
 	if queued := peer.TrySend(BlockchainChannel, msgBytes); !queued {
 		return fmt.Errorf("peer queue full")
 	}
@@ -89,7 +107,11 @@ func (sio *switchIO) sendBlockNotFound(height int64, peerID p2p.ID) error {
 	if peer == nil {
 		return fmt.Errorf("peer not found")
 	}
-	msgBytes := cdc.MustMarshalBinaryBare(&bcNoBlockResponseMessage{Height: height})
+	msgBytes, err := bc.EncodeMsg(&bcproto.NoBlockResponse{Height: height})
+	if err != nil {
+		return err
+	}
+
 	if queued := peer.TrySend(BlockchainChannel, msgBytes); !queued {
 		return fmt.Errorf("peer queue full")
 	}
@@ -105,14 +127,18 @@ func (sio *switchIO) trySwitchToConsensus(state state.State, skipWAL bool) bool
 	return ok
 }
 
-func (sio *switchIO) broadcastStatusRequest(base int64, height int64) {
+func (sio *switchIO) broadcastStatusRequest(base, height int64) error {
 	if height == 0 && base > 0 {
 		base = 0
 	}
-	msgBytes := cdc.MustMarshalBinaryBare(&bcStatusRequestMessage{
-		Base:   base,
-		Height: height,
-	})
+
+	msgBytes, err := bc.EncodeMsg(&bcproto.StatusRequest{Base: base, Height: height})
+	if err != nil {
+		return err
+	}
+
 	// XXX: maybe we should use an io specific peer list here
 	sio.sw.Broadcast(BlockchainChannel, msgBytes)
+
+	return nil
 }
diff --git a/blockchain/v2/reactor.go b/blockchain/v2/reactor.go
index 8a7019b55..57a692f8f 100644
--- a/blockchain/v2/reactor.go
+++ b/blockchain/v2/reactor.go
@@ -6,11 +6,11 @@ import (
 	"sync"
 	"time"
 
-	"github.com/tendermint/go-amino"
-
 	"github.com/tendermint/tendermint/behaviour"
+	bc "github.com/tendermint/tendermint/blockchain"
 	"github.com/tendermint/tendermint/libs/log"
 	"github.com/tendermint/tendermint/p2p"
+	bcproto "github.com/tendermint/tendermint/proto/blockchain"
 	"github.com/tendermint/tendermint/state"
 	"github.com/tendermint/tendermint/types"
 )
@@ -20,109 +20,6 @@ const (
 	chBufferSize int = 1000
 )
 
-//-------------------------------------
-
-type bcBlockRequestMessage struct {
-	Height int64
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcBlockRequestMessage) ValidateBasic() error {
-	if m.Height < 0 {
-		return errors.New("negative Height")
-	}
-	return nil
-}
-
-func (m *bcBlockRequestMessage) String() string {
-	return fmt.Sprintf("[bcBlockRequestMessage %v]", m.Height)
-}
-
-type bcNoBlockResponseMessage struct {
-	Height int64
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcNoBlockResponseMessage) ValidateBasic() error {
-	if m.Height < 0 {
-		return errors.New("negative Height")
-	}
-	return nil
-}
-
-func (m *bcNoBlockResponseMessage) String() string {
-	return fmt.Sprintf("[bcNoBlockResponseMessage %d]", m.Height)
-}
-
-//-------------------------------------
-
-type bcBlockResponseMessage struct {
-	Block *types.Block
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcBlockResponseMessage) ValidateBasic() error {
-	if m.Block == nil {
-		return errors.New("block response message has nil block")
-	}
-
-	return m.Block.ValidateBasic()
-}
-
-func (m *bcBlockResponseMessage) String() string {
-	return fmt.Sprintf("[bcBlockResponseMessage %v]", m.Block.Height)
-}
-
-//-------------------------------------
-
-type bcStatusRequestMessage struct {
-	Height int64
-	Base   int64
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcStatusRequestMessage) ValidateBasic() error {
-	if m.Base < 0 {
-		return errors.New("negative Base")
-	}
-	if m.Height < 0 {
-		return errors.New("negative Height")
-	}
-	if m.Base > m.Height {
-		return fmt.Errorf("base %v cannot be greater than height %v", m.Base, m.Height)
-	}
-	return nil
-}
-
-func (m *bcStatusRequestMessage) String() string {
-	return fmt.Sprintf("[bcStatusRequestMessage %v:%v]", m.Base, m.Height)
-}
-
-//-------------------------------------
-
-type bcStatusResponseMessage struct {
-	Height int64
-	Base   int64
-}
-
-// ValidateBasic performs basic validation.
-func (m *bcStatusResponseMessage) ValidateBasic() error {
-	if m.Base < 0 {
-		return errors.New("negative Base")
-	}
-	if m.Height < 0 {
-		return errors.New("negative Height")
-	}
-	if m.Base > m.Height {
-		return fmt.Errorf("base %v cannot be greater than height %v", m.Base, m.Height)
-	}
-	return nil
-}
-
-func (m *bcStatusResponseMessage) String() string {
-	return fmt.Sprintf("[bcStatusResponseMessage %v:%v]", m.Base, m.Height)
-}
-
 type blockStore interface {
 	LoadBlock(height int64) *types.Block
 	SaveBlock(*types.Block, *types.PartSet, *types.Commit)
@@ -512,38 +409,9 @@ func (r *BlockchainReactor) Stop() error {
 	return nil
 }
 
-const (
-	// NOTE: keep up to date with bcBlockResponseMessage
-	bcBlockResponseMessagePrefixSize   = 4
-	bcBlockResponseMessageFieldKeySize = 1
-	maxMsgSize                         = types.MaxBlockSizeBytes +
-		bcBlockResponseMessagePrefixSize +
-		bcBlockResponseMessageFieldKeySize
-)
-
-// BlockchainMessage is a generic message for this reactor.
-type BlockchainMessage interface {
-	ValidateBasic() error
-}
-
-// RegisterBlockchainMessages registers the fast sync messages for amino encoding.
-func RegisterBlockchainMessages(cdc *amino.Codec) {
-	cdc.RegisterInterface((*BlockchainMessage)(nil), nil)
-	cdc.RegisterConcrete(&bcBlockRequestMessage{}, "tendermint/blockchain/BlockRequest", nil)
-	cdc.RegisterConcrete(&bcBlockResponseMessage{}, "tendermint/blockchain/BlockResponse", nil)
-	cdc.RegisterConcrete(&bcNoBlockResponseMessage{}, "tendermint/blockchain/NoBlockResponse", nil)
-	cdc.RegisterConcrete(&bcStatusResponseMessage{}, "tendermint/blockchain/StatusResponse", nil)
-	cdc.RegisterConcrete(&bcStatusRequestMessage{}, "tendermint/blockchain/StatusRequest", nil)
-}
-
-func decodeMsg(bz []byte) (msg BlockchainMessage, err error) {
-	err = cdc.UnmarshalBinaryBare(bz, &msg)
-	return
-}
-
 // Receive implements Reactor by handling different message types.
 func (r *BlockchainReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte) {
-	msg, err := decodeMsg(msgBytes)
+	msg, err := bc.DecodeMsg(msgBytes)
 	if err != nil {
 		r.logger.Error("error decoding message",
 			"src", src.ID(), "chId", chID, "msg", msg, "err", err, "bytes", msgBytes)
@@ -551,7 +419,7 @@ func (r *BlockchainReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte) {
 		return
 	}
 
-	if err = msg.ValidateBasic(); err != nil {
+	if err = bc.ValidateMsg(msg); err != nil {
 		r.logger.Error("peer sent us invalid msg", "peer", src, "msg", msg, "err", err)
 		_ = r.reporter.Report(behaviour.BadMessage(src.ID(), err.Error()))
 		return
@@ -560,12 +428,12 @@ func (r *BlockchainReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte) {
 	r.logger.Debug("Receive", "src", src.ID(), "chID", chID, "msg", msg)
 
 	switch msg := msg.(type) {
-	case *bcStatusRequestMessage:
+	case *bcproto.StatusRequest:
 		if err := r.io.sendStatusResponse(r.store.Base(), r.store.Height(), src.ID()); err != nil {
 			r.logger.Error("Could not send status message to peer", "src", src)
 		}
 
-	case *bcBlockRequestMessage:
+	case *bcproto.BlockRequest:
 		block := r.store.LoadBlock(msg.Height)
 		if block != nil {
 			if err = r.io.sendBlockToPeer(block, src.ID()); err != nil {
@@ -579,26 +447,31 @@ func (r *BlockchainReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte) {
 			}
 		}
 
-	case *bcStatusResponseMessage:
+	case *bcproto.StatusResponse:
 		r.mtx.RLock()
 		if r.events != nil {
 			r.events <- bcStatusResponse{peerID: src.ID(), base: msg.Base, height: msg.Height}
 		}
 		r.mtx.RUnlock()
 
-	case *bcBlockResponseMessage:
+	case *bcproto.BlockResponse:
 		r.mtx.RLock()
+		bi, err := types.BlockFromProto(msg.Block)
+		if err != nil {
+			r.logger.Error("error transitioning block from protobuf", "err", err)
+			return
+		}
 		if r.events != nil {
 			r.events <- bcBlockResponse{
 				peerID: src.ID(),
-				block:  msg.Block,
+				block:  bi,
 				size:   int64(len(msgBytes)),
 				time:   time.Now(),
 			}
 		}
 		r.mtx.RUnlock()
 
-	case *bcNoBlockResponseMessage:
+	case *bcproto.NoBlockResponse:
 		r.mtx.RLock()
 		if r.events != nil {
 			r.events <- bcNoBlockResponse{peerID: src.ID(), height: msg.Height, time: time.Now()}
@@ -640,7 +513,7 @@ func (r *BlockchainReactor) GetChannels() []*p2p.ChannelDescriptor {
 			Priority:            10,
 			SendQueueCapacity:   2000,
 			RecvBufferCapacity:  50 * 4096,
-			RecvMessageCapacity: maxMsgSize,
+			RecvMessageCapacity: bc.MaxMsgSize,
 		},
 	}
 }
diff --git a/blockchain/v2/reactor_test.go b/blockchain/v2/reactor_test.go
index ef6cb20f9..59b29d34d 100644
--- a/blockchain/v2/reactor_test.go
+++ b/blockchain/v2/reactor_test.go
@@ -14,12 +14,14 @@ import (
 
 	abci "github.com/tendermint/tendermint/abci/types"
 	"github.com/tendermint/tendermint/behaviour"
+	bc "github.com/tendermint/tendermint/blockchain"
 	cfg "github.com/tendermint/tendermint/config"
 	"github.com/tendermint/tendermint/libs/log"
 	"github.com/tendermint/tendermint/libs/service"
 	"github.com/tendermint/tendermint/mempool/mock"
 	"github.com/tendermint/tendermint/p2p"
 	"github.com/tendermint/tendermint/p2p/conn"
+	bcproto "github.com/tendermint/tendermint/proto/blockchain"
 	"github.com/tendermint/tendermint/proxy"
 	sm "github.com/tendermint/tendermint/state"
 	"github.com/tendermint/tendermint/store"
@@ -124,7 +126,8 @@ func (sio *mockSwitchIo) trySwitchToConsensus(state sm.State, skipWAL bool) bool
 	return true
 }
 
-func (sio *mockSwitchIo) broadcastStatusRequest(base int64, height int64) {
+func (sio *mockSwitchIo) broadcastStatusRequest(base int64, height int64) error {
+	return nil
 }
 
 type testReactorParams struct {
@@ -370,10 +373,10 @@ func TestReactorHelperMode(t *testing.T) {
 			name:   "status request",
 			params: params,
 			msgs: []testEvent{
-				{"P1", bcStatusRequestMessage{}},
-				{"P1", bcBlockRequestMessage{Height: 13}},
-				{"P1", bcBlockRequestMessage{Height: 20}},
-				{"P1", bcBlockRequestMessage{Height: 22}},
+				{"P1", bcproto.StatusRequest{}},
+				{"P1", bcproto.BlockRequest{Height: 13}},
+				{"P1", bcproto.BlockRequest{Height: 20}},
+				{"P1", bcproto.BlockRequest{Height: 22}},
 			},
 		},
 	}
@@ -389,18 +392,25 @@ func TestReactorHelperMode(t *testing.T) {
 			for i := 0; i < len(tt.msgs); i++ {
 				step := tt.msgs[i]
 				switch ev := step.event.(type) {
-				case bcStatusRequestMessage:
+				case bcproto.StatusRequest:
 					old := mockSwitch.numStatusResponse
-					reactor.Receive(channelID, mockPeer{id: p2p.ID(step.peer)}, cdc.MustMarshalBinaryBare(ev))
+					msg, err := bc.EncodeMsg(&ev)
+					assert.NoError(t, err)
+					reactor.Receive(channelID, mockPeer{id: p2p.ID(step.peer)}, msg)
 					assert.Equal(t, old+1, mockSwitch.numStatusResponse)
-				case bcBlockRequestMessage:
+				case bcproto.BlockRequest:
 					if ev.Height > params.startHeight {
 						old := mockSwitch.numNoBlockResponse
-						reactor.Receive(channelID, mockPeer{id: p2p.ID(step.peer)}, cdc.MustMarshalBinaryBare(ev))
+						msg, err := bc.EncodeMsg(&ev)
+						assert.NoError(t, err)
+						reactor.Receive(channelID, mockPeer{id: p2p.ID(step.peer)}, msg)
 						assert.Equal(t, old+1, mockSwitch.numNoBlockResponse)
 					} else {
 						old := mockSwitch.numBlockResponse
-						reactor.Receive(channelID, mockPeer{id: p2p.ID(step.peer)}, cdc.MustMarshalBinaryBare(ev))
+						msg, err := bc.EncodeMsg(&ev)
+						assert.NoError(t, err)
+						assert.NoError(t, err)
+						reactor.Receive(channelID, mockPeer{id: p2p.ID(step.peer)}, msg)
 						assert.Equal(t, old+1, mockSwitch.numBlockResponse)
 					}
 				}
diff --git a/config/toml.go b/config/toml.go
index 2349607c8..2343b1646 100644
--- a/config/toml.go
+++ b/config/toml.go
@@ -345,7 +345,7 @@ temp_dir = "{{ .StateSync.TempDir }}"
 # Fast Sync version to use:
 #   1) "v0" (default) - the legacy fast sync implementation
 #   2) "v1" - refactor of v0 version for better testability
-#   3) "v2" - refactor of v1 version for better usability
+#   2) "v2" - complete redesign of v0, optimized for testability & readability 
 version = "{{ .FastSync.Version }}"
 
 ##### consensus configuration options #####
diff --git a/consensus/reactor.go b/consensus/reactor.go
index 01a435035..9faea561f 100644
--- a/consensus/reactor.go
+++ b/consensus/reactor.go
@@ -1047,8 +1047,8 @@ func (ps *PeerState) PickVoteToSend(votes types.VoteSetReader) (vote *types.Vote
 		return nil, false
 	}
 
-	height, round, votesType, size := votes.GetHeight(), votes.GetRound(),
-		tmproto.SignedMsgType(votes.Type()), votes.Size()
+	height, round, votesType, size :=
+		votes.GetHeight(), votes.GetRound(), tmproto.SignedMsgType(votes.Type()), votes.Size()
 
 	// Lazily set data using 'votes'.
 	if votes.IsCommit() {
diff --git a/docs/tendermint-core/configuration.md b/docs/tendermint-core/configuration.md
index 4bebd11dd..777035e2b 100644
--- a/docs/tendermint-core/configuration.md
+++ b/docs/tendermint-core/configuration.md
@@ -263,6 +263,7 @@ max_tx_bytes = 1048576
 # Fast Sync version to use:
 #   1) "v0" (default) - the legacy fast sync implementation
 #   2) "v1" - refactor of v0 version for better testability
+#   2) "v2" - complete redesign of v0, optimized for testability & readability
 version = "v0"
 
 ##### consensus configuration options #####
diff --git a/go.mod b/go.mod
index cee169a6a..83f2c3710 100644
--- a/go.mod
+++ b/go.mod
@@ -30,4 +30,5 @@ require (
 	golang.org/x/crypto v0.0.0-20200406173513-056763e48d71
 	golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e
 	google.golang.org/grpc v1.29.1
+	google.golang.org/protobuf v1.23.0 // indirect
 )
diff --git a/go.sum b/go.sum
index 0d851b851..a64356153 100644
--- a/go.sum
+++ b/go.sum
@@ -160,7 +160,6 @@ github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5y
 github.com/golang/protobuf v1.3.2 h1:6nsPYzhq5kReh6QImI3k5qWzO4PEbvbIW2cwSfR/6xs=
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.3/go.mod h1:vzj43D7+SQXF/4pzW/hwtAqwc6iTitCiVSaWz5lYuqw=
-github.com/golang/protobuf v1.3.5/go.mod h1:6O5/vntMXwX2lRkT1hjjk0nAC1IDOTvTlVgjlRvqsdk=
 github.com/golang/protobuf v1.4.0-rc.1/go.mod h1:ceaxUfeHdC40wWswd/P6IGgMaK3YpKi5j83Wpe3EHw8=
 github.com/golang/protobuf v1.4.0-rc.1.0.20200221234624-67d41d38c208/go.mod h1:xKAWHe0F5eneWXFV3EuXVDTCmh+JuBKY0li0aMyXATA=
 github.com/golang/protobuf v1.4.0-rc.2/go.mod h1:LlEzMj4AhA7rCAGe4KMBDvJI+AwstrUpVNzEA03Pprs=
@@ -653,6 +652,8 @@ google.golang.org/protobuf v0.0.0-20200228230310-ab0ca4ff8a60/go.mod h1:cfTl7dwQ
 google.golang.org/protobuf v1.20.1-0.20200309200217-e05f789c0967/go.mod h1:A+miEFZTKqfCUM6K7xSMQL9OKL/b6hQv+e19PK+JZNE=
 google.golang.org/protobuf v1.21.0 h1:qdOKuR/EIArgaWNjetjgTzgVTAZ+S/WXVrq9HW9zimw=
 google.golang.org/protobuf v1.21.0/go.mod h1:47Nbq4nVaFHyn7ilMalzfO3qCViNmqZ2kzikPIcrTAo=
+google.golang.org/protobuf v1.23.0 h1:4MY060fB1DLGMB/7MBTLnwQUY6+F09GEiz6SsrNqyzM=
+google.golang.org/protobuf v1.23.0/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2l/sGQquU=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
diff --git a/proto/blockchain/msgs.pb.go b/proto/blockchain/msgs.pb.go
index 68e402f08..bd9c7de16 100644
--- a/proto/blockchain/msgs.pb.go
+++ b/proto/blockchain/msgs.pb.go
@@ -5,7 +5,6 @@ package blockchain
 
 import (
 	fmt "fmt"
-	_ "github.com/gogo/protobuf/gogoproto"
 	proto "github.com/gogo/protobuf/proto"
 	types "github.com/tendermint/tendermint/proto/types"
 	io "io"
@@ -116,7 +115,7 @@ func (m *NoBlockResponse) GetHeight() int64 {
 
 // BlockResponse returns block to the requested
 type BlockResponse struct {
-	Block types.Block `protobuf:"bytes,1,opt,name=block,proto3" json:"block"`
+	Block *types.Block `protobuf:"bytes,1,opt,name=block,proto3" json:"block,omitempty"`
 }
 
 func (m *BlockResponse) Reset()         { *m = BlockResponse{} }
@@ -152,11 +151,11 @@ func (m *BlockResponse) XXX_DiscardUnknown() {
 
 var xxx_messageInfo_BlockResponse proto.InternalMessageInfo
 
-func (m *BlockResponse) GetBlock() types.Block {
+func (m *BlockResponse) GetBlock() *types.Block {
 	if m != nil {
 		return m.Block
 	}
-	return types.Block{}
+	return nil
 }
 
 // StatusRequest requests the status of a node (Height & Base)
@@ -401,33 +400,31 @@ func init() {
 func init() { proto.RegisterFile("proto/blockchain/msgs.proto", fileDescriptor_ecf660069f8bb334) }
 
 var fileDescriptor_ecf660069f8bb334 = []byte{
-	// 401 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x8c, 0x93, 0x41, 0x4f, 0xe2, 0x40,
-	0x14, 0xc7, 0xdb, 0x2d, 0xb0, 0xc9, 0x83, 0x42, 0xb6, 0x87, 0x5d, 0x02, 0xd9, 0xee, 0xa6, 0x07,
-	0x22, 0x6a, 0xda, 0x88, 0x27, 0xa3, 0xa7, 0x9e, 0x88, 0x46, 0x63, 0x4a, 0xe2, 0x81, 0x0b, 0x69,
-	0x61, 0xd2, 0x36, 0xda, 0x4e, 0xed, 0x4c, 0x0f, 0x7c, 0x0b, 0x3f, 0x92, 0x47, 0x8e, 0x1c, 0x3d,
-	0x19, 0x03, 0x5f, 0xc4, 0x30, 0x53, 0x0a, 0xad, 0x8a, 0xdc, 0x66, 0xfe, 0x7d, 0xef, 0xf7, 0xfe,
-	0xf3, 0xfe, 0x29, 0xb4, 0xa3, 0x18, 0x53, 0x6c, 0x38, 0x0f, 0x78, 0x7c, 0x3f, 0xf6, 0x6c, 0x3f,
-	0x34, 0x02, 0xe2, 0x12, 0x9d, 0xa9, 0x4a, 0x9b, 0xa2, 0x70, 0x82, 0xe2, 0xc0, 0x0f, 0x29, 0x57,
-	0xf4, 0x4d, 0x5d, 0xab, 0x43, 0x3d, 0x3f, 0x9e, 0x8c, 0x22, 0x3b, 0xa6, 0x53, 0x83, 0x53, 0x5c,
-	0xec, 0xe2, 0xcd, 0x89, 0xb7, 0xb4, 0xfe, 0x70, 0x85, 0x4e, 0x23, 0x44, 0xf8, 0x1c, 0xfe, 0x41,
-	0xeb, 0x40, 0xcd, 0x5c, 0x5d, 0x2d, 0xf4, 0x98, 0x20, 0x42, 0x95, 0xdf, 0x50, 0xf1, 0x90, 0xef,
-	0x7a, 0xb4, 0x29, 0xfe, 0x17, 0x0f, 0x24, 0x2b, 0xbd, 0x69, 0x5d, 0x68, 0xdc, 0xe0, 0xb4, 0x92,
-	0x44, 0x38, 0x24, 0xe8, 0xcb, 0xd2, 0x4b, 0x90, 0xf3, 0x85, 0x67, 0x50, 0x66, 0x23, 0x59, 0x5d,
-	0xb5, 0xf7, 0x57, 0xff, 0xf0, 0x22, 0xe6, 0x4b, 0x67, 0x5d, 0x66, 0x69, 0xf6, 0xfa, 0x4f, 0xb0,
-	0x78, 0x87, 0x76, 0x0e, 0xf2, 0x80, 0xda, 0x34, 0x21, 0xdf, 0xf8, 0x53, 0x14, 0x28, 0x39, 0x36,
-	0x41, 0xcd, 0x1f, 0x4c, 0x65, 0x67, 0xed, 0x02, 0xea, 0xeb, 0xe6, 0xdd, 0x96, 0x3f, 0xed, 0x7e,
-	0x96, 0xe0, 0xe7, 0x35, 0x22, 0xc4, 0x76, 0x91, 0x72, 0x0b, 0x32, 0xf3, 0x33, 0x8a, 0xb9, 0x8d,
-	0xf4, 0x25, 0x5d, 0x7d, 0x47, 0x36, 0xfa, 0xf6, 0x5e, 0xfb, 0x82, 0x55, 0x73, 0xb6, 0xf7, 0x3c,
-	0x84, 0x5f, 0x21, 0x1e, 0xad, 0xa1, 0xdc, 0x1e, 0x1b, 0x5f, 0xed, 0x1d, 0xef, 0xa4, 0x16, 0x52,
-	0xe8, 0x0b, 0x56, 0x23, 0x2c, 0x04, 0x33, 0x80, 0x7a, 0x01, 0x2c, 0x31, 0xf0, 0xe1, 0x3e, 0x76,
-	0x33, 0xac, 0xec, 0x14, 0xa1, 0x84, 0x2d, 0x33, 0xdb, 0x41, 0x69, 0x0f, 0x68, 0x2e, 0xbc, 0x15,
-	0x94, 0xe4, 0xd2, 0xbc, 0x83, 0x46, 0x06, 0x4d, 0xad, 0x96, 0x19, 0xf5, 0x68, 0x2f, 0x6a, 0xe6,
-	0xb5, 0x4e, 0x72, 0x8a, 0x59, 0x06, 0x89, 0x24, 0x81, 0x79, 0x35, 0x5b, 0xa8, 0xe2, 0x7c, 0xa1,
-	0x8a, 0x6f, 0x0b, 0x55, 0x7c, 0x5a, 0xaa, 0xc2, 0x7c, 0xa9, 0x0a, 0x2f, 0x4b, 0x55, 0x18, 0x9e,
-	0xb8, 0x3e, 0xf5, 0x12, 0x47, 0x1f, 0xe3, 0xc0, 0xd8, 0x4c, 0xda, 0x3e, 0x16, 0x7f, 0x49, 0xa7,
-	0xc2, 0x94, 0xd3, 0xf7, 0x00, 0x00, 0x00, 0xff, 0xff, 0xaf, 0xc4, 0x3a, 0x27, 0xad, 0x03, 0x00,
-	0x00,
+	// 371 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x8c, 0x93, 0xc1, 0x4e, 0xf2, 0x40,
+	0x14, 0x85, 0xdb, 0xbf, 0xc0, 0x9f, 0x5c, 0x28, 0xc4, 0x2e, 0x94, 0x48, 0x6c, 0x4c, 0x17, 0x46,
+	0xd4, 0x0c, 0x11, 0x96, 0xba, 0x22, 0x2e, 0x48, 0x8c, 0xc6, 0x94, 0xc4, 0x05, 0x1b, 0xd2, 0xe2,
+	0xa4, 0x6d, 0xb4, 0x1d, 0xe4, 0x4e, 0x17, 0xbe, 0x85, 0x8f, 0xe4, 0xd2, 0x25, 0x4b, 0x97, 0x06,
+	0x5e, 0xc4, 0x30, 0x53, 0x0a, 0xad, 0x8a, 0xec, 0x66, 0x6e, 0xce, 0xf9, 0xe6, 0xf4, 0xdc, 0x14,
+	0x1a, 0xe3, 0x09, 0xe3, 0xac, 0xe5, 0x3e, 0xb1, 0xd1, 0xe3, 0xc8, 0x77, 0x82, 0xa8, 0x15, 0xa2,
+	0x87, 0x44, 0x4c, 0x8d, 0x06, 0xa7, 0xd1, 0x03, 0x9d, 0x84, 0x41, 0xc4, 0xe5, 0x84, 0xac, 0x74,
+	0xfb, 0x7b, 0xd2, 0xc9, 0x5f, 0xc6, 0x14, 0xa5, 0x5f, 0x6a, 0xac, 0x23, 0xa8, 0x74, 0x17, 0x57,
+	0x9b, 0x3e, 0xc7, 0x14, 0xb9, 0xb1, 0x0b, 0x25, 0x9f, 0x06, 0x9e, 0xcf, 0xeb, 0xea, 0xa1, 0x7a,
+	0xac, 0xd9, 0xc9, 0xcd, 0x6a, 0x42, 0xed, 0x96, 0x25, 0x4a, 0x1c, 0xb3, 0x08, 0xe9, 0xaf, 0xd2,
+	0x2b, 0xd0, 0xb3, 0xc2, 0x0e, 0x14, 0xc5, 0x93, 0x42, 0x57, 0x6e, 0x1f, 0x90, 0x6f, 0x49, 0x45,
+	0x2e, 0x22, 0x5d, 0x52, 0x6b, 0x5d, 0x80, 0xde, 0xe7, 0x0e, 0x8f, 0xf1, 0x8f, 0x64, 0x86, 0x01,
+	0x05, 0xd7, 0x41, 0x5a, 0xff, 0x27, 0xa6, 0xe2, 0x6c, 0x5d, 0x42, 0x75, 0x69, 0xde, 0x1c, 0xf6,
+	0x47, 0xf7, 0x9b, 0x06, 0xff, 0x6f, 0x28, 0xa2, 0xe3, 0x51, 0xe3, 0x0e, 0x74, 0x91, 0x67, 0x38,
+	0x91, 0x31, 0x92, 0x6f, 0x68, 0x92, 0x0d, 0x6d, 0x93, 0xf5, 0x46, 0x7b, 0x8a, 0x5d, 0x71, 0xd7,
+	0x1b, 0x1e, 0xc0, 0x4e, 0xc4, 0x86, 0x4b, 0xa8, 0x8c, 0x27, 0x9e, 0x2f, 0xb7, 0xcf, 0x36, 0x52,
+	0x73, 0xfd, 0xf7, 0x14, 0xbb, 0x16, 0xe5, 0x56, 0xd2, 0x87, 0x6a, 0x0e, 0xac, 0x09, 0xf0, 0xc9,
+	0x36, 0x71, 0x53, 0xac, 0xee, 0xe6, 0xa1, 0x28, 0xca, 0x4c, 0x3b, 0x28, 0x6c, 0x01, 0xcd, 0x2c,
+	0x6f, 0x01, 0xc5, 0xcc, 0x36, 0xef, 0xa1, 0x96, 0x42, 0x93, 0xa8, 0x45, 0x41, 0x3d, 0xdd, 0x8a,
+	0x9a, 0x66, 0xad, 0x62, 0x66, 0xd2, 0x2d, 0x82, 0x86, 0x71, 0xd8, 0xbd, 0x7e, 0x9f, 0x99, 0xea,
+	0x74, 0x66, 0xaa, 0x9f, 0x33, 0x53, 0x7d, 0x9d, 0x9b, 0xca, 0x74, 0x6e, 0x2a, 0x1f, 0x73, 0x53,
+	0x19, 0x9c, 0x7b, 0x01, 0xf7, 0x63, 0x97, 0x8c, 0x58, 0xd8, 0x5a, 0xbd, 0xb4, 0x7e, 0xcc, 0xff,
+	0x64, 0x6e, 0x49, 0x4c, 0x3a, 0x5f, 0x01, 0x00, 0x00, 0xff, 0xff, 0x55, 0x3b, 0x57, 0xfa, 0x7f,
+	0x03, 0x00, 0x00,
 }
 
 func (m *BlockRequest) Marshal() (dAtA []byte, err error) {
@@ -506,16 +503,18 @@ func (m *BlockResponse) MarshalToSizedBuffer(dAtA []byte) (int, error) {
 	_ = i
 	var l int
 	_ = l
-	{
-		size, err := m.Block.MarshalToSizedBuffer(dAtA[:i])
-		if err != nil {
-			return 0, err
+	if m.Block != nil {
+		{
+			size, err := m.Block.MarshalToSizedBuffer(dAtA[:i])
+			if err != nil {
+				return 0, err
+			}
+			i -= size
+			i = encodeVarintMsgs(dAtA, i, uint64(size))
 		}
-		i -= size
-		i = encodeVarintMsgs(dAtA, i, uint64(size))
+		i--
+		dAtA[i] = 0xa
 	}
-	i--
-	dAtA[i] = 0xa
 	return len(dAtA) - i, nil
 }
 
@@ -763,8 +762,10 @@ func (m *BlockResponse) Size() (n int) {
 	}
 	var l int
 	_ = l
-	l = m.Block.Size()
-	n += 1 + l + sovMsgs(uint64(l))
+	if m.Block != nil {
+		l = m.Block.Size()
+		n += 1 + l + sovMsgs(uint64(l))
+	}
 	return n
 }
 
@@ -1079,6 +1080,9 @@ func (m *BlockResponse) Unmarshal(dAtA []byte) error {
 			if postIndex > l {
 				return io.ErrUnexpectedEOF
 			}
+			if m.Block == nil {
+				m.Block = &types.Block{}
+			}
 			if err := m.Block.Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
 				return err
 			}
diff --git a/proto/blockchain/msgs.proto b/proto/blockchain/msgs.proto
index f6e10f8d3..8e7cbf50b 100644
--- a/proto/blockchain/msgs.proto
+++ b/proto/blockchain/msgs.proto
@@ -3,7 +3,6 @@ package tendermint.proto.blockchain;
 
 option go_package = "github.com/tendermint/tendermint/proto/blockchain";
 
-import "third_party/proto/gogoproto/gogo.proto";
 import "proto/types/block.proto";
 
 // BlockRequest requests a block for a specific height
@@ -18,7 +17,7 @@ message NoBlockResponse {
 
 // BlockResponse returns block to the requested
 message BlockResponse {
-  tendermint.proto.types.Block block = 1 [(gogoproto.nullable) = false];
+  tendermint.proto.types.Block block = 1;
 }
 
 // StatusRequest requests the status of a node (Height & Base)
diff --git a/types/block.go b/types/block.go
index 28365e774..0aedbe3e2 100644
--- a/types/block.go
+++ b/types/block.go
@@ -839,6 +839,7 @@ func (commit *Commit) ValidateBasic() error {
 	if commit.Round < 0 {
 		return errors.New("negative Round")
 	}
+
 	if commit.Height >= 1 {
 		if commit.BlockID.IsZero() {
 			return errors.New("commit cannot be for nil block")
@@ -853,7 +854,6 @@ func (commit *Commit) ValidateBasic() error {
 			}
 		}
 	}
-
 	return nil
 }
 
diff --git a/types/block_test.go b/types/block_test.go
index 74ffe1f2b..06dce55d9 100644
--- a/types/block_test.go
+++ b/types/block_test.go
@@ -602,44 +602,18 @@ func TestBlockIDValidateBasic(t *testing.T) {
 	}
 }
 
-func makeRandHeader() Header {
-	chainID := "test"
-	t := time.Now()
-	height := tmrand.Int63()
-	randBytes := tmrand.Bytes(tmhash.Size)
-	randAddress := tmrand.Bytes(crypto.AddressSize)
-	h := Header{
-		Version:            version.Consensus{Block: 1, App: 1},
-		ChainID:            chainID,
-		Height:             height,
-		Time:               t,
-		LastBlockID:        BlockID{},
-		LastCommitHash:     randBytes,
-		DataHash:           randBytes,
-		ValidatorsHash:     randBytes,
-		NextValidatorsHash: randBytes,
-		ConsensusHash:      randBytes,
-		AppHash:            randBytes,
-
-		LastResultsHash: randBytes,
-
-		EvidenceHash:    randBytes,
-		ProposerAddress: randAddress,
-	}
-
-	return h
-}
-
 func TestBlockProtoBuf(t *testing.T) {
 	h := tmrand.Int63()
 	c1 := randCommit(time.Now())
 	b1 := MakeBlock(h, []Tx{Tx([]byte{1})}, &Commit{Signatures: []CommitSig{}}, []Evidence{})
 	b1.ProposerAddress = tmrand.Bytes(crypto.AddressSize)
+
 	b2 := MakeBlock(h, []Tx{Tx([]byte{1})}, c1, []Evidence{})
 	b2.ProposerAddress = tmrand.Bytes(crypto.AddressSize)
 	evi := NewMockEvidence(b2.Height, time.Now(), tmrand.Bytes(32))
 	b2.Evidence = EvidenceData{Evidence: EvidenceList{evi}}
 	b2.EvidenceHash = b2.Evidence.Hash()
+
 	b3 := MakeBlock(h, []Tx{}, c1, []Evidence{})
 	b3.ProposerAddress = tmrand.Bytes(crypto.AddressSize)
 	testCases := []struct {
@@ -679,7 +653,6 @@ func TestDataProtoBuf(t *testing.T) {
 	_ = data.Hash()
 	data2 := &Data{Txs: Txs{}}
 	_ = data2.Hash()
-
 	testCases := []struct {
 		msg     string
 		data1   *Data
@@ -700,6 +673,74 @@ func TestDataProtoBuf(t *testing.T) {
 	}
 }
 
+func TestEvidenceDataProtoBuf(t *testing.T) {
+	val := NewMockPV()
+	blockID := makeBlockID(tmhash.Sum([]byte("blockhash")), math.MaxInt32, tmhash.Sum([]byte("partshash")))
+	blockID2 := makeBlockID(tmhash.Sum([]byte("blockhash2")), math.MaxInt32, tmhash.Sum([]byte("partshash")))
+	const chainID = "mychain"
+	v := makeVote(t, val, chainID, math.MaxInt32, math.MaxInt64, 1, 0x01, blockID, time.Now())
+	v2 := makeVote(t, val, chainID, math.MaxInt32, math.MaxInt64, 2, 0x01, blockID2, time.Now())
+	ev := NewDuplicateVoteEvidence(v2, v)
+	data := &EvidenceData{Evidence: EvidenceList{ev}}
+	_ = data.Hash()
+	testCases := []struct {
+		msg      string
+		data1    *EvidenceData
+		expPass1 bool
+		expPass2 bool
+	}{
+		{"success", data, true, true},
+		{"empty evidenceData", &EvidenceData{Evidence: EvidenceList{}}, true, true},
+		{"fail nil Data", nil, false, false},
+	}
+
+	for _, tc := range testCases {
+		protoData, err := tc.data1.ToProto()
+		if tc.expPass1 {
+			require.NoError(t, err, tc.msg)
+		} else {
+			require.Error(t, err, tc.msg)
+		}
+
+		eviD := new(EvidenceData)
+		err = eviD.FromProto(protoData)
+		if tc.expPass2 {
+			require.NoError(t, err, tc.msg)
+			require.Equal(t, tc.data1, eviD, tc.msg)
+		} else {
+			require.Error(t, err, tc.msg)
+		}
+	}
+}
+
+func makeRandHeader() Header {
+	chainID := "test"
+	t := time.Now()
+	height := tmrand.Int63()
+	randBytes := tmrand.Bytes(tmhash.Size)
+	randAddress := tmrand.Bytes(crypto.AddressSize)
+	h := Header{
+		Version:            version.Consensus{Block: 1, App: 1},
+		ChainID:            chainID,
+		Height:             height,
+		Time:               t,
+		LastBlockID:        BlockID{},
+		LastCommitHash:     randBytes,
+		DataHash:           randBytes,
+		ValidatorsHash:     randBytes,
+		NextValidatorsHash: randBytes,
+		ConsensusHash:      randBytes,
+		AppHash:            randBytes,
+
+		LastResultsHash: randBytes,
+
+		EvidenceHash:    randBytes,
+		ProposerAddress: randAddress,
+	}
+
+	return h
+}
+
 func TestHeaderProto(t *testing.T) {
 	h1 := makeRandHeader()
 	tc := []struct {
@@ -779,70 +820,3 @@ func TestSignedHeaderProtoBuf(t *testing.T) {
 		}
 	}
 }
-
-func TestEvidenceDataProtoBuf(t *testing.T) {
-	val := NewMockPV()
-	blockID := makeBlockID(tmhash.Sum([]byte("blockhash")), math.MaxInt32, tmhash.Sum([]byte("partshash")))
-	blockID2 := makeBlockID(tmhash.Sum([]byte("blockhash2")), math.MaxInt32, tmhash.Sum([]byte("partshash")))
-	const chainID = "mychain"
-	v := makeVote(t, val, chainID, math.MaxInt32, math.MaxInt64, 1, 0x01, blockID, time.Now())
-	v2 := makeVote(t, val, chainID, math.MaxInt32, math.MaxInt64, 2, 0x01, blockID2, time.Now())
-	ev := NewDuplicateVoteEvidence(v2, v)
-	data := &EvidenceData{Evidence: EvidenceList{ev}}
-	_ = data.Hash()
-	testCases := []struct {
-		msg      string
-		data1    *EvidenceData
-		expPass1 bool
-		expPass2 bool
-	}{
-		{"success", data, true, true},
-		{"empty evidenceData", &EvidenceData{Evidence: EvidenceList{}}, true, true},
-		{"fail nil Data", nil, false, false},
-	}
-
-	for _, tc := range testCases {
-		protoData, err := tc.data1.ToProto()
-		if tc.expPass1 {
-			require.NoError(t, err, tc.msg)
-		} else {
-			require.Error(t, err, tc.msg)
-		}
-
-		eviD := new(EvidenceData)
-		err = eviD.FromProto(protoData)
-		if tc.expPass2 {
-			require.NoError(t, err, tc.msg)
-			require.Equal(t, tc.data1, eviD, tc.msg)
-		} else {
-			require.Error(t, err, tc.msg)
-		}
-	}
-}
-func TestCommitProtoBuf(t *testing.T) {
-	commit := randCommit(time.Now())
-
-	testCases := []struct {
-		msg     string
-		c1      *Commit
-		expPass bool
-	}{
-		{"success", commit, true},
-		// Empty value sets signatures to nil, signatures should not be nillable
-		{"empty commit", &Commit{Signatures: []CommitSig{}}, true},
-		{"fail Commit nil", nil, false},
-	}
-	for _, tc := range testCases {
-		tc := tc
-		protoCommit := tc.c1.ToProto()
-
-		c, err := CommitFromProto(protoCommit)
-
-		if tc.expPass {
-			require.NoError(t, err, tc.msg)
-			require.Equal(t, tc.c1, c, tc.msg)
-		} else {
-			require.Error(t, err, tc.msg)
-		}
-	}
-}