diff --git a/contracts/value/value.go b/contracts/value/value.go
index b0fb0a8aa..6e1a6b831 100644
--- a/contracts/value/value.go
+++ b/contracts/value/value.go
@@ -44,6 +44,9 @@ const (
 	// credentialAllCommand defines the credential command that is allowed to
 	// perform all commands.
 	credentialAllCommand = "all"
+
+	// contractKeyPrefix is used to prefix keys in the K/V store.
+	contractKeyPrefix = "VALU" // intentionally 4 bytes only, not a typo!
 )
 
 // Command defines a type of command for the value contract
@@ -172,14 +175,17 @@ func (c valueCommand) write(snap store.Snapshot, step execution.Step) error {
 		return xerrors.Errorf("'%s' not found in tx arg", ValueArg)
 	}
 
-	err := snap.Set(key, value)
+	snapKey := prefix(key)
+	err := snap.Set(snapKey, value)
 	if err != nil {
 		return xerrors.Errorf("failed to set value: %v", err)
 	}
 
 	c.index[string(key)] = struct{}{}
 
-	dela.Logger.Info().Str("contract", ContractName).Msgf("setting %x=%s", key, value)
+	dela.Logger.Info().
+		Str("contract", ContractName).
+		Msgf("setting value %x=%s", snapKey, value)
 
 	return nil
 }
@@ -191,7 +197,7 @@ func (c valueCommand) read(snap store.Snapshot, step execution.Step) error {
 		return xerrors.Errorf("'%s' not found in tx arg", KeyArg)
 	}
 
-	val, err := snap.Get(key)
+	val, err := snap.Get(prefix(key))
 	if err != nil {
 		return xerrors.Errorf("failed to get key '%s': %v", key, err)
 	}
@@ -208,13 +214,18 @@ func (c valueCommand) delete(snap store.Snapshot, step execution.Step) error {
 		return xerrors.Errorf("'%s' not found in tx arg", KeyArg)
 	}
 
-	err := snap.Delete(key)
+	snapKey := prefix(key)
+	err := snap.Delete(snapKey)
 	if err != nil {
 		return xerrors.Errorf("failed to delete key '%x': %v", key, err)
 	}
 
 	delete(c.index, string(key))
 
+	dela.Logger.Info().
+		Str("contract", ContractName).
+		Msgf("deleting value %x", snapKey)
+
 	return nil
 }
 
@@ -223,7 +234,7 @@ func (c valueCommand) list(snap store.Snapshot) error {
 	res := []string{}
 
 	for k := range c.index {
-		v, err := snap.Get([]byte(k))
+		v, err := snap.Get(prefix([]byte(k)))
 		if err != nil {
 			return xerrors.Errorf("failed to get key '%s': %v", k, err)
 		}
@@ -247,3 +258,7 @@ func (h infoLog) Write(p []byte) (int, error) {
 
 	return len(p), nil
 }
+
+func prefix(key []byte) []byte {
+	return append([]byte(contractKeyPrefix), key...)
+}
diff --git a/contracts/value/value_test.go b/contracts/value/value_test.go
index 00b3ed75a..c358793cd 100644
--- a/contracts/value/value_test.go
+++ b/contracts/value/value_test.go
@@ -76,7 +76,7 @@ func TestCommand_Write(t *testing.T) {
 	_, found = contract.index["dummy"]
 	require.True(t, found)
 
-	res, err := snap.Get([]byte("dummy"))
+	res, err := snap.Get(prefix([]byte("dummy")))
 	require.NoError(t, err)
 	require.Equal(t, "value", string(res))
 }
@@ -98,7 +98,7 @@ func TestCommand_Read(t *testing.T) {
 	require.EqualError(t, err, fake.Err("failed to get key 'dummy'"))
 
 	snap := fake.NewSnapshot()
-	snap.Set(key, []byte("value"))
+	snap.Set(prefix(key), []byte("value"))
 
 	buf := &bytes.Buffer{}
 	cmd.Contract.printer = buf
@@ -127,13 +127,13 @@ func TestCommand_Delete(t *testing.T) {
 	require.EqualError(t, err, fake.Err("failed to delete key '"+keyHex+"'"))
 
 	snap := fake.NewSnapshot()
-	snap.Set(key, []byte("value"))
+	snap.Set(prefix(key), []byte("value"))
 	contract.index[keyStr] = struct{}{}
 
 	err = cmd.delete(snap, makeStep(t, KeyArg, keyStr))
 	require.NoError(t, err)
 
-	res, err := snap.Get(key)
+	res, err := snap.Get(prefix(key))
 	require.Nil(t, err)
 	require.Nil(t, res)
 
@@ -158,8 +158,8 @@ func TestCommand_List(t *testing.T) {
 	}
 
 	snap := fake.NewSnapshot()
-	snap.Set([]byte(key1), []byte("value1"))
-	snap.Set([]byte(key2), []byte("value2"))
+	snap.Set(prefix([]byte(key1)), []byte("value1"))
+	snap.Set(prefix([]byte(key2)), []byte("value2"))
 
 	err := cmd.list(snap)
 	require.NoError(t, err)
diff --git a/test/integration_test.go b/test/integration_test.go
index e4882e708..3a1441eef 100644
--- a/test/integration_test.go
+++ b/test/integration_test.go
@@ -87,7 +87,7 @@ func getTest[T require.TestingT](numNode, numTx int) func(t T) {
 		require.NoError(t, err)
 
 		for i := 0; i < numTx; i++ {
-			key := make([]byte, 32)
+			key := make([]byte, 28) // only 224 bits are available
 
 			_, err = rand.Read(key)
 			require.NoError(t, err)
@@ -102,7 +102,7 @@ func getTest[T require.TestingT](numNode, numTx int) func(t T) {
 			err = addAndWait(t, timeout, manager, nodes[0].(cosiDelaNode), args...)
 			require.NoError(t, err)
 
-			proof, err := nodes[0].GetOrdering().GetProof(key)
+			proof, err := nodes[0].GetOrdering().GetProof(append([]byte("VALU"), key...))
 			require.NoError(t, err)
 			require.Equal(t, []byte("value1"), proof.GetValue())
 		}
@@ -112,7 +112,13 @@ func getTest[T require.TestingT](numNode, numTx int) func(t T) {
 // -----------------------------------------------------------------------------
 // Utility functions
 
-func addAndWait(t require.TestingT, to time.Duration, manager txn.Manager, node cosiDelaNode, args ...txn.Arg) error {
+func addAndWait(
+	t require.TestingT,
+	to time.Duration,
+	manager txn.Manager,
+	node cosiDelaNode,
+	args ...txn.Arg,
+) error {
 	manager.Sync()
 
 	tx, err := manager.Make(args...)