diff --git a/util/keys/trail.go b/util/keys/trail.go
deleted file mode 100644
index bb1ff121..00000000
--- a/util/keys/trail.go
+++ /dev/null
@@ -1,59 +0,0 @@
-// Copyright © 2016 Abcum Ltd
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package keys
-
-import (
-	"fmt"
-	"time"
-)
-
-// Trail ...
-type Trail struct {
-	KV interface{}
-	NS interface{}
-	DB interface{}
-	TB interface{}
-	TK interface{}
-	AT time.Time
-}
-
-// init initialises the key
-func (k *Trail) init() *Trail {
-	// k.TK = "¤"
-	k.TK = "*"
-	k.TB = "history"
-	if k.AT.IsZero() {
-		k.AT = time.Now()
-	}
-	return k
-}
-
-// Encode encodes the key into binary
-func (k *Trail) Encode() []byte {
-	k.init()
-	return encode(k.KV, k.NS, k.DB, k.TB, k.TK, k.AT)
-}
-
-// Decode decodes the key from binary
-func (k *Trail) Decode(data []byte) {
-	k.init()
-	decode(data, &k.KV, &k.NS, &k.DB, &k.TB, &k.TK, &k.AT)
-}
-
-// String returns a string representation of the key
-func (k *Trail) String() string {
-	k.init()
-	return fmt.Sprintf("/%s/%s/%s/%s/%s/%s/%s/%s", k.KV, k.NS, k.DB, k.TB, k.TK, k.AT.Format(time.RFC3339Nano))
-}