diff --git a/sign.go b/sign.go
index 1805e2a..b01d2f3 100644
--- a/sign.go
+++ b/sign.go
@@ -3,12 +3,7 @@ package supplierrpc
 import (
 	"crypto/md5"
 	"encoding/hex"
-	"errors"
-	"strconv"
 	"strings"
-	"time"
-
-	"git.tetele.net/tgo/crypter"
 )
 
 /**