diff --git a/Gopkg.lock b/Gopkg.lock
index 6e1c41493..17b74d74b 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -286,7 +286,7 @@
     "leveldb/table",
     "leveldb/util"
   ]
-  revision = "0d5a0ceb10cf9ab89fdd744cc8c50a83134f6697"
+  revision = "e2150783cd35f5b607daca48afd8c57ec54cc995"
 
 [[projects]]
   branch = "master"
diff --git a/docs/spec/blockchain/encoding.md b/docs/spec/blockchain/encoding.md
index df056ab2b..16902d099 100644
--- a/docs/spec/blockchain/encoding.md
+++ b/docs/spec/blockchain/encoding.md
@@ -151,7 +151,15 @@ func MakeParts(obj interface{}, partSize int) []Part
 
 Simple Merkle trees are used in numerous places in Tendermint to compute a cryptographic digest of a data structure.
 
-RIPEMD160 is always used as the hashing function.
+Tendermint always uses the `TMHASH` hash function, which is the first 20-bytes
+of the SHA256:
+
+```
+func TMHASH(bz []byte) []byte {
+    shasum := SHA256(bz)
+    return shasum[:20]
+}
+```
 
 ### Simple Merkle Root
 
@@ -174,7 +182,7 @@ func SimpleMerkleRoot(hashes [][]byte) []byte{
 func SimpleConcatHash(left, right []byte) []byte{
     left = encodeByteSlice(left)
     right = encodeByteSlice(right)
-    return RIPEMD160 (append(left, right))
+    return TMHASH(append(left, right))
 }
 ```
 
@@ -182,8 +190,8 @@ Note that the leaves are Amino encoded as byte-arrays (ie. simple Uvarint length
 prefix) before being concatenated together and hashed.
 
 Note: we will abuse notion and invoke `SimpleMerkleRoot` with arguments of type `struct` or type `[]struct`.
-For `struct` arguments, we compute a `[][]byte` by sorting elements of the `struct` according to
-field name and then hashing them.
+For `struct` arguments, we compute a `[][]byte` containing the hash of each
+field in the struct sorted by the hash of the field name.
 For `[]struct` arguments, we compute a `[][]byte` by hashing the individual `struct` elements.
 
 ### Simple Merkle Proof
diff --git a/types/block.go b/types/block.go
index c3a399f67..bc018ee89 100644
--- a/types/block.go
+++ b/types/block.go
@@ -8,9 +8,9 @@ import (
 	"sync"
 	"time"
 
+	"github.com/tendermint/tendermint/crypto/merkle"
+	"github.com/tendermint/tendermint/crypto/tmhash"
 	cmn "github.com/tendermint/tendermint/libs/common"
-	"github.com/tendermint/tendermint/libs/merkle"
-	"golang.org/x/crypto/ripemd160"
 )
 
 // Block defines the atomic unit of a Tendermint blockchain.
@@ -552,7 +552,7 @@ type hasher struct {
 }
 
 func (h hasher) Hash() []byte {
-	hasher := ripemd160.New()
+	hasher := tmhash.New()
 	if h.item != nil && !cmn.IsTypedNil(h.item) && !cmn.IsEmpty(h.item) {
 		bz, err := cdc.MarshalBinaryBare(h.item)
 		if err != nil {
diff --git a/types/evidence.go b/types/evidence.go
index a83e2cd00..266375ec3 100644
--- a/types/evidence.go
+++ b/types/evidence.go
@@ -5,8 +5,9 @@ import (
 	"fmt"
 
 	"github.com/tendermint/go-amino"
+
 	"github.com/tendermint/tendermint/crypto"
-	"github.com/tendermint/tendermint/libs/merkle"
+	"github.com/tendermint/tendermint/crypto/merkle"
 )
 
 // ErrEvidenceInvalid wraps a piece of evidence and the error denoting how or why it is invalid.
@@ -180,7 +181,7 @@ type EvidenceList []Evidence
 // Hash returns the simple merkle root hash of the EvidenceList.
 func (evl EvidenceList) Hash() []byte {
 	// Recursive impl.
-	// Copied from tmlibs/merkle to avoid allocations
+	// Copied from crypto/merkle to avoid allocations
 	switch len(evl) {
 	case 0:
 		return nil
diff --git a/types/params.go b/types/params.go
index e2117ed4c..3056c82a0 100644
--- a/types/params.go
+++ b/types/params.go
@@ -2,8 +2,8 @@ package types
 
 import (
 	abci "github.com/tendermint/tendermint/abci/types"
+	"github.com/tendermint/tendermint/crypto/merkle"
 	cmn "github.com/tendermint/tendermint/libs/common"
-	"github.com/tendermint/tendermint/libs/merkle"
 )
 
 const (
diff --git a/types/part_set.go b/types/part_set.go
index 7116176d3..f6d7f6b6e 100644
--- a/types/part_set.go
+++ b/types/part_set.go
@@ -7,10 +7,9 @@ import (
 	"io"
 	"sync"
 
-	"golang.org/x/crypto/ripemd160"
-
+	"github.com/tendermint/tendermint/crypto/merkle"
+	"github.com/tendermint/tendermint/crypto/tmhash"
 	cmn "github.com/tendermint/tendermint/libs/common"
-	"github.com/tendermint/tendermint/libs/merkle"
 )
 
 var (
@@ -31,7 +30,7 @@ func (part *Part) Hash() []byte {
 	if part.hash != nil {
 		return part.hash
 	}
-	hasher := ripemd160.New()
+	hasher := tmhash.New()
 	hasher.Write(part.Bytes) // nolint: errcheck, gas
 	part.hash = hasher.Sum(nil)
 	return part.hash
diff --git a/types/results.go b/types/results.go
index d9381420a..7f8e6093a 100644
--- a/types/results.go
+++ b/types/results.go
@@ -2,8 +2,8 @@ package types
 
 import (
 	abci "github.com/tendermint/tendermint/abci/types"
+	"github.com/tendermint/tendermint/crypto/merkle"
 	cmn "github.com/tendermint/tendermint/libs/common"
-	"github.com/tendermint/tendermint/libs/merkle"
 )
 
 //-----------------------------------------------------------------------------
@@ -51,6 +51,8 @@ func (a ABCIResults) Bytes() []byte {
 
 // Hash returns a merkle hash of all results
 func (a ABCIResults) Hash() []byte {
+	// NOTE: we copy the impl of the merkle tree for txs -
+	// we should be consistent and either do it for both or not.
 	return merkle.SimpleHashFromHashers(a.toHashers())
 }
 
diff --git a/types/tx.go b/types/tx.go
index d02dc7a17..489f0b232 100644
--- a/types/tx.go
+++ b/types/tx.go
@@ -6,19 +6,19 @@ import (
 	"fmt"
 
 	abci "github.com/tendermint/tendermint/abci/types"
+	"github.com/tendermint/tendermint/crypto/merkle"
+	"github.com/tendermint/tendermint/crypto/tmhash"
 	cmn "github.com/tendermint/tendermint/libs/common"
-	"github.com/tendermint/tendermint/libs/merkle"
 )
 
 // Tx is an arbitrary byte array.
 // NOTE: Tx has no types at this level, so when wire encoded it's just length-prefixed.
-// Alternatively, it may make sense to add types here and let
-// []byte be type 0x1 so we can have versioned txs if need be in the future.
+// Might we want types here ?
 type Tx []byte
 
-// Hash computes the RIPEMD160 hash of the wire encoded transaction.
+// Hash computes the TMHASH hash of the wire encoded transaction.
 func (tx Tx) Hash() []byte {
-	return aminoHasher(tx).Hash()
+	return tmhash.Sum(tx)
 }
 
 // String returns the hex-encoded transaction as a string.
@@ -32,7 +32,7 @@ type Txs []Tx
 // Hash returns the simple Merkle root hash of the transactions.
 func (txs Txs) Hash() []byte {
 	// Recursive impl.
-	// Copied from tmlibs/merkle to avoid allocations
+	// Copied from tendermint/crypto/merkle to avoid allocations
 	switch len(txs) {
 	case 0:
 		return nil
diff --git a/types/validator_set.go b/types/validator_set.go
index 6c39f5be2..191f8b428 100644
--- a/types/validator_set.go
+++ b/types/validator_set.go
@@ -7,8 +7,8 @@ import (
 	"sort"
 	"strings"
 
+	"github.com/tendermint/tendermint/crypto/merkle"
 	cmn "github.com/tendermint/tendermint/libs/common"
-	"github.com/tendermint/tendermint/libs/merkle"
 )
 
 // ValidatorSet represent a set of *Validator at a given height.