diff --git a/merkledag/merkledag.go b/merkledag/merkledag.go
index 56f020113..9529bc543 100644
--- a/merkledag/merkledag.go
+++ b/merkledag/merkledag.go
@@ -72,7 +72,7 @@ func (n *Node) Multihash() (mh.Multihash, error) {
 		return nil, err
 	}
 
-	return mh.Sum(b, mh.SHA2_256, -1)
+	return u.Hash(b)
 }
 
 func (n *Node) Key() (u.Key, error) {
diff --git a/util/util.go b/util/util.go
index 1cf6e7d88..6d0e3dd74 100644
--- a/util/util.go
+++ b/util/util.go
@@ -2,6 +2,7 @@ package util
 
 import (
 	"fmt"
+	mh "github.com/jbenet/go-multihash"
 	"os"
 )
 
@@ -11,6 +12,11 @@ var NotImplementedError = fmt.Errorf("Error: not implemented yet.")
 // a Key for maps. It's a string (rep of a multihash).
 type Key string
 
+// global hash function. uses multihash SHA2_256, 256 bits
+func Hash(data []byte) (mh.Multihash, error) {
+	return mh.Sum(data, mh.SHA2_256, -1)
+}
+
 // Shorthand printing functions.
 func PErr(format string, a ...interface{}) {
 	fmt.Fprintf(os.Stderr, format, a...)