diff --git a/src/server.py b/src/server.py
--- a/src/server.py
+++ b/src/server.py
@@ -1,10 +1,9 @@
-import hashlib
-import socket
+import socket
 import ssl
 import multiprocessing
 import logging as log
 
-from hashtree import HashTree
+from hashtree import HashTree,hashBlock
 from networkers import NetworkReader,NetworkWriter
 import config as conf
 
@@ -140,7 +139,7 @@ class Server:
 		self._dataFile.write(binData)
 		self._lastIndex=i
 		if self._treeFile:
-			self._newLeaves[i+self._tree.leafStart]=hashlib.sha256(binData).digest()[HashTree.HASH_LEN:]
+			self._newLeaves[i+self._tree.leafStart]=hashBlock(binData)
 
 		return ({"command": "ack", "index": i},)