diff --git a/sign.go b/sign.go
index 892a7e9..05d61d3 100644
--- a/sign.go
+++ b/sign.go
@@ -3,9 +3,7 @@ package msgrpc
 import (
 	"crypto/md5"
 	"encoding/hex"
-	"encoding/json"
 	"errors"
-	"log"
 	"strconv"
 	"strings"
 	"time"