diff --git a/src/utils/utils.go b/src/utils/utils.go
index b57530f..d148e10 100644
--- a/src/utils/utils.go
+++ b/src/utils/utils.go
@@ -6,6 +6,7 @@ import (
 	"crypto/md5"
 	"crypto/rand"
 	"crypto/sha256"
+	"encoding/hex"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -89,7 +90,7 @@ func XXHashFile(fname string) (hash256 []byte, err error) {
 func SHA256(s string) string {
 	sha := sha256.New()
 	sha.Write([]byte(s))
-	return fmt.Sprintf("%x", sha.Sum(nil))
+	return hex.EncodeToString(sha.Sum(nil))
 }
 
 // PublicIP returns public ip address
diff --git a/src/utils/utils_test.go b/src/utils/utils_test.go
index 102beb8..496d59f 100644
--- a/src/utils/utils_test.go
+++ b/src/utils/utils_test.go
@@ -40,6 +40,13 @@ func BenchmarkImoHash(b *testing.B) {
 	}
 }
 
+func BenchmarkSha256(b *testing.B) {
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		SHA256("hello,world")
+	}
+}
+
 func TestExists(t *testing.T) {
 	bigFile()
 	defer os.Remove("bigfile.test")