diff --git a/types/block.go b/types/block.go
index 6aa97c2d6..b9b541a96 100644
--- a/types/block.go
+++ b/types/block.go
@@ -12,6 +12,7 @@ import (
 	"github.com/tendermint/go-wire/data"
 	cmn "github.com/tendermint/tmlibs/common"
 	"github.com/tendermint/tmlibs/merkle"
+	"golang.org/x/crypto/ripemd160"
 )
 
 // Block defines the atomic unit of a Tendermint blockchain.
@@ -179,20 +180,20 @@ func (h *Header) Hash() data.Bytes {
 	if len(h.ValidatorsHash) == 0 {
 		return nil
 	}
-	return merkle.SimpleHashFromMap(map[string]interface{}{
-		"ChainID":     h.ChainID,
-		"Height":      h.Height,
-		"Time":        h.Time,
-		"NumTxs":      h.NumTxs,
-		"TotalTxs":    h.TotalTxs,
-		"LastBlockID": h.LastBlockID,
-		"LastCommit":  h.LastCommitHash,
-		"Data":        h.DataHash,
-		"Validators":  h.ValidatorsHash,
-		"App":         h.AppHash,
-		"Consensus":   h.ConsensusHash,
-		"Results":     h.LastResultsHash,
-		"Evidence":    h.EvidenceHash,
+	return merkle.SimpleHashFromMap(map[string]merkle.Hasher{
+		"ChainID":     wireHasher(h.ChainID),
+		"Height":      wireHasher(h.Height),
+		"Time":        wireHasher(h.Time),
+		"NumTxs":      wireHasher(h.NumTxs),
+		"TotalTxs":    wireHasher(h.TotalTxs),
+		"LastBlockID": wireHasher(h.LastBlockID),
+		"LastCommit":  wireHasher(h.LastCommitHash),
+		"Data":        wireHasher(h.DataHash),
+		"Validators":  wireHasher(h.ValidatorsHash),
+		"App":         wireHasher(h.AppHash),
+		"Consensus":   wireHasher(h.ConsensusHash),
+		"Results":     wireHasher(h.LastResultsHash),
+		"Evidence":    wireHasher(h.EvidenceHash),
 	})
 }
 
@@ -356,11 +357,11 @@ func (commit *Commit) ValidateBasic() error {
 // Hash returns the hash of the commit
 func (commit *Commit) Hash() data.Bytes {
 	if commit.hash == nil {
-		bs := make([]interface{}, len(commit.Precommits))
+		bs := make([]merkle.Hasher, len(commit.Precommits))
 		for i, precommit := range commit.Precommits {
-			bs[i] = precommit
+			bs[i] = wireHasher(precommit)
 		}
-		commit.hash = merkle.SimpleHashFromBinaries(bs)
+		commit.hash = merkle.SimpleHashFromHashers(bs)
 	}
 	return commit.hash
 }
@@ -510,3 +511,23 @@ func (blockID BlockID) WriteSignBytes(w io.Writer, n *int, err *error) {
 func (blockID BlockID) String() string {
 	return fmt.Sprintf(`%v:%v`, blockID.Hash, blockID.PartsHeader)
 }
+
+//-------------------------------------------------------
+
+type hasher struct {
+	item interface{}
+}
+
+func (h hasher) Hash() []byte {
+	hasher, n, err := ripemd160.New(), new(int), new(error)
+	wire.WriteBinary(h.item, hasher, n, err)
+	if *err != nil {
+		panic(err)
+	}
+	return hasher.Sum(nil)
+
+}
+
+func wireHasher(item interface{}) merkle.Hasher {
+	return hasher{item}
+}
diff --git a/types/event_bus.go b/types/event_bus.go
index 6b6069b90..4edaea588 100644
--- a/types/event_bus.go
+++ b/types/event_bus.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 
-	abci "github.com/tendermint/abci/types"
 	cmn "github.com/tendermint/tmlibs/common"
 	"github.com/tendermint/tmlibs/log"
 	tmpubsub "github.com/tendermint/tmlibs/pubsub"
@@ -98,17 +97,11 @@ func (b *EventBus) PublishEventTx(event EventDataTx) error {
 	// validate and fill tags from tx result
 	for _, tag := range event.Result.Tags {
 		// basic validation
-		if tag.Key == "" {
+		if len(tag.Key) == 0 {
 			b.Logger.Info("Got tag with an empty key (skipping)", "tag", tag, "tx", event.Tx)
 			continue
 		}
-
-		switch tag.ValueType {
-		case abci.KVPair_STRING:
-			tags[tag.Key] = tag.ValueString
-		case abci.KVPair_INT:
-			tags[tag.Key] = tag.ValueInt
-		}
+		tags[string(tag.Key)] = tag.Value
 	}
 
 	// add predefined tags
diff --git a/types/evidence.go b/types/evidence.go
index 3ae3e40b1..9973c62e6 100644
--- a/types/evidence.go
+++ b/types/evidence.go
@@ -120,7 +120,7 @@ func (dve *DuplicateVoteEvidence) Index() int {
 
 // Hash returns the hash of the evidence.
 func (dve *DuplicateVoteEvidence) Hash() []byte {
-	return merkle.SimpleHashFromBinary(dve)
+	return wireHasher(dve).Hash()
 }
 
 // Verify returns an error if the two votes aren't conflicting.
@@ -165,7 +165,9 @@ func (dve *DuplicateVoteEvidence) Equal(ev Evidence) bool {
 	}
 
 	// just check their hashes
-	return bytes.Equal(merkle.SimpleHashFromBinary(dve), merkle.SimpleHashFromBinary(ev))
+	dveHash := wireHasher(dve).Hash()
+	evHash := wireHasher(ev).Hash()
+	return bytes.Equal(dveHash, evHash)
 }
 
 //-----------------------------------------------------------------
diff --git a/types/params.go b/types/params.go
index 90ab5f659..0e8ac577f 100644
--- a/types/params.go
+++ b/types/params.go
@@ -106,13 +106,13 @@ func (params *ConsensusParams) Validate() error {
 // Hash returns a merkle hash of the parameters to store
 // in the block header
 func (params *ConsensusParams) Hash() []byte {
-	return merkle.SimpleHashFromMap(map[string]interface{}{
-		"block_gossip_part_size_bytes": params.BlockGossip.BlockPartSizeBytes,
-		"block_size_max_bytes":         params.BlockSize.MaxBytes,
-		"block_size_max_gas":           params.BlockSize.MaxGas,
-		"block_size_max_txs":           params.BlockSize.MaxTxs,
-		"tx_size_max_bytes":            params.TxSize.MaxBytes,
-		"tx_size_max_gas":              params.TxSize.MaxGas,
+	return merkle.SimpleHashFromMap(map[string]merkle.Hasher{
+		"block_gossip_part_size_bytes": wireHasher(params.BlockGossip.BlockPartSizeBytes),
+		"block_size_max_bytes":         wireHasher(params.BlockSize.MaxBytes),
+		"block_size_max_gas":           wireHasher(params.BlockSize.MaxGas),
+		"block_size_max_txs":           wireHasher(params.BlockSize.MaxTxs),
+		"tx_size_max_bytes":            wireHasher(params.TxSize.MaxBytes),
+		"tx_size_max_gas":              wireHasher(params.TxSize.MaxGas),
 	})
 }
 
diff --git a/types/part_set.go b/types/part_set.go
index e8a0997c0..d922e34d6 100644
--- a/types/part_set.go
+++ b/types/part_set.go
@@ -96,7 +96,7 @@ func NewPartSetFromData(data []byte, partSize int) *PartSet {
 	// divide data into 4kb parts.
 	total := (len(data) + partSize - 1) / partSize
 	parts := make([]*Part, total)
-	parts_ := make([]merkle.Hashable, total)
+	parts_ := make([]merkle.Hasher, total)
 	partsBitArray := cmn.NewBitArray(total)
 	for i := 0; i < total; i++ {
 		part := &Part{
@@ -108,7 +108,7 @@ func NewPartSetFromData(data []byte, partSize int) *PartSet {
 		partsBitArray.SetIndex(i, true)
 	}
 	// Compute merkle proofs
-	root, proofs := merkle.SimpleProofsFromHashables(parts_)
+	root, proofs := merkle.SimpleProofsFromHashers(parts_)
 	for i := 0; i < total; i++ {
 		parts[i].Proof = *proofs[i]
 	}
diff --git a/types/protobuf.go b/types/protobuf.go
index 43c8f4505..bac5b799e 100644
--- a/types/protobuf.go
+++ b/types/protobuf.go
@@ -23,15 +23,15 @@ func (tm2pb) Header(header *Header) *types.Header {
 	}
 }
 
-func (tm2pb) BlockID(blockID BlockID) *types.BlockID {
-	return &types.BlockID{
+func (tm2pb) BlockID(blockID BlockID) types.BlockID {
+	return types.BlockID{
 		Hash:  blockID.Hash,
 		Parts: TM2PB.PartSetHeader(blockID.PartsHeader),
 	}
 }
 
-func (tm2pb) PartSetHeader(partSetHeader PartSetHeader) *types.PartSetHeader {
-	return &types.PartSetHeader{
+func (tm2pb) PartSetHeader(partSetHeader PartSetHeader) types.PartSetHeader {
+	return types.PartSetHeader{
 		Total: int32(partSetHeader.Total), // XXX: overflow
 		Hash:  partSetHeader.Hash,
 	}
diff --git a/types/results.go b/types/results.go
index 29420fbc0..8e79e1ac7 100644
--- a/types/results.go
+++ b/types/results.go
@@ -47,20 +47,20 @@ func (a ABCIResults) Bytes() []byte {
 
 // Hash returns a merkle hash of all results
 func (a ABCIResults) Hash() []byte {
-	return merkle.SimpleHashFromHashables(a.toHashables())
+	return merkle.SimpleHashFromHashers(a.toHashers())
 }
 
 // ProveResult returns a merkle proof of one result from the set
 func (a ABCIResults) ProveResult(i int) merkle.SimpleProof {
-	_, proofs := merkle.SimpleProofsFromHashables(a.toHashables())
+	_, proofs := merkle.SimpleProofsFromHashers(a.toHashers())
 	return *proofs[i]
 }
 
-func (a ABCIResults) toHashables() []merkle.Hashable {
+func (a ABCIResults) toHashers() []merkle.Hasher {
 	l := len(a)
-	hashables := make([]merkle.Hashable, l)
+	hashers := make([]merkle.Hasher, l)
 	for i := 0; i < l; i++ {
-		hashables[i] = a[i]
+		hashers[i] = a[i]
 	}
-	return hashables
+	return hashers
 }
diff --git a/types/signable.go b/types/signable.go
index 2134f6300..bfdf9faa1 100644
--- a/types/signable.go
+++ b/types/signable.go
@@ -5,7 +5,6 @@ import (
 	"io"
 
 	cmn "github.com/tendermint/tmlibs/common"
-	"github.com/tendermint/tmlibs/merkle"
 )
 
 // Signable is an interface for all signable things.
@@ -23,8 +22,3 @@ func SignBytes(chainID string, o Signable) []byte {
 	}
 	return buf.Bytes()
 }
-
-// HashSignBytes is a convenience method for getting the hash of the bytes of a signable
-func HashSignBytes(chainID string, o Signable) []byte {
-	return merkle.SimpleHashFromBinary(SignBytes(chainID, o))
-}
diff --git a/types/tx.go b/types/tx.go
index 4cf5843ae..db42ed8e7 100644
--- a/types/tx.go
+++ b/types/tx.go
@@ -18,7 +18,7 @@ type Tx []byte
 
 // Hash computes the RIPEMD160 hash of the go-wire encoded transaction.
 func (tx Tx) Hash() []byte {
-	return merkle.SimpleHashFromBinary(tx)
+	return wireHasher(tx).Hash()
 }
 
 // String returns the hex-encoded transaction as a string.
@@ -72,11 +72,11 @@ func (txs Txs) IndexByHash(hash []byte) int {
 // TODO: optimize this!
 func (txs Txs) Proof(i int) TxProof {
 	l := len(txs)
-	hashables := make([]merkle.Hashable, l)
+	hashers := make([]merkle.Hasher, l)
 	for i := 0; i < l; i++ {
-		hashables[i] = txs[i]
+		hashers[i] = txs[i]
 	}
-	root, proofs := merkle.SimpleProofsFromHashables(hashables)
+	root, proofs := merkle.SimpleProofsFromHashers(hashers)
 
 	return TxProof{
 		Index:    i,
diff --git a/types/validator_set.go b/types/validator_set.go
index 7e895aba0..0d6c3249e 100644
--- a/types/validator_set.go
+++ b/types/validator_set.go
@@ -54,7 +54,7 @@ func (valSet *ValidatorSet) IncrementAccum(times int) {
 	for _, val := range valSet.Validators {
 		// check for overflow both multiplication and sum
 		val.Accum = safeAddClip(val.Accum, safeMulClip(val.VotingPower, int64(times)))
-		validatorsHeap.Push(val, accumComparable{val})
+		validatorsHeap.PushComparable(val, accumComparable{val})
 	}
 
 	// Decrement the validator with most accum times times
@@ -150,11 +150,11 @@ func (valSet *ValidatorSet) Hash() []byte {
 	if len(valSet.Validators) == 0 {
 		return nil
 	}
-	hashables := make([]merkle.Hashable, len(valSet.Validators))
+	hashers := make([]merkle.Hasher, len(valSet.Validators))
 	for i, val := range valSet.Validators {
-		hashables[i] = val
+		hashers[i] = val
 	}
-	return merkle.SimpleHashFromHashables(hashables)
+	return merkle.SimpleHashFromHashers(hashers)
 }
 
 func (valSet *ValidatorSet) Add(val *Validator) (added bool) {