diff --git a/q7/sysutils.py b/q7/sysutils.py
index 1233ebb..187e41e 100644
--- a/q7/sysutils.py
+++ b/q7/sysutils.py
@@ -1,6 +1,8 @@
 # -*- coding: utf-8 -*-
 #!/usr/bin/python
 
+import binascii
+
 def xPrint(text):
     print(text, flush=True)
 
@@ -8,3 +10,7 @@ def getDaySeconds(time_val, incdays):
     time_zone = 8
     return int((time_val + time_zone * 3600)/3600/24 + incdays) * 3600 * 24 - 3600 * time_zone;
 
+def crc32(data):
+    hash_code = binascii.crc32(data)
+    assert hash_code >= 0
+    return hash_code