diff --git a/src/client.py b/src/client.py
--- a/src/client.py
+++ b/src/client.py
@@ -1,5 +1,6 @@
 import collections
 import socket
+import ssl
 import logging as log
 from datetime import datetime
 
@@ -11,8 +12,10 @@ from networkers import NetworkReader,Net
 
 
 class Connection:
-	def __init__(self):
-		self._socket=socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+	def __init__(self,sslContext):
+		sock=socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+
+		self._socket=sslContext.wrap_socket(sock)
 		self._socket.connect((conf.hosts[0], conf.port))
 		fr=self._socket.makefile(mode="rb")
 		fw=self._socket.makefile(mode="wb")
@@ -24,6 +27,7 @@ class Connection:
 		return self.incoming,self.outcoming
 
 	def __exit__(self, exc_type, exc_val, exc_tb):
+		self._socket.shutdown(socket.SHUT_RDWR)
 		self._socket.close()
 
 
@@ -31,6 +35,10 @@ class Client:
 	def __init__(self,filename):
 		self._filename=filename
 
+		self._ssl=ssl.create_default_context(cafile=conf.peers)
+		self._ssl.check_hostname=False
+		self._ssl.load_cert_chain(conf.certfile,conf.keyfile)
+
 	def negotiate(self):
 		print(datetime.now(), "initializing...")
 		localTree=HashTree.fromFile(self._filename)
@@ -38,7 +46,7 @@ class Client:
 		nodeStack=collections.deque([0]) # root
 
 		# initialize session
-		with Connection() as (incoming,outcoming):
+		with Connection(self._ssl) as (incoming,outcoming):
 			jsonData={"command":"init", "blockSize":localTree.BLOCK_SIZE, "blockCount":localTree.leafCount, "version":conf.version}
 			outcoming.writeMsg(jsonData)
 			jsonData,binData=incoming.readMsg()
@@ -49,7 +57,7 @@ class Client:
 			progress=Progress(localTree.leafCount)
 			while len(nodeStack)>0:
 				i=nodeStack.pop()
-				outcoming.writeMsg({"command":"req", "index":i})
+				outcoming.writeMsg({"command":"req", "index":i, "dataType":"hash"})
 
 				jsonData,binData=incoming.readMsg()
 				assert jsonData["index"]==i
@@ -73,7 +81,7 @@ class Client:
 		i1=-1
 
 		print(datetime.now(), "sending data:")
-		with Connection() as (incoming,outcoming):
+		with Connection(self._ssl) as (incoming,outcoming):
 			progress=Progress(len(blocksToTransfer))
 			for (k,i2) in enumerate(blocksToTransfer):
 				jsonData={"command":"send", "index":i2, "dataType":"data"}
@@ -91,7 +99,7 @@ class Client:
 				progress.p(k)
 		progress.done()
 
-		with Connection() as (incoming,outcoming):
+		with Connection(self._ssl) as (incoming,outcoming):
 			outcoming.writeMsg({"command":"end"})
 
 		log.info("closing session...")