diff --git a/mods/udp_srv.py b/mods/udp_srv.py
new file mode 100644
index 0000000..edf7db4
--- /dev/null
+++ b/mods/udp_srv.py
@@ -0,0 +1,78 @@
+import socketserver
+import pickle
+import simplecrypto
+from uuid import uuid4
+
+BUFSIZE = 8192
+BLOCKSIZE = 4096
+
+PACKET_TYPE_RECV_RESULT = 'recv_result'
+PACKET_TYPE_DATA_FRAGMENT = 'data_fragment'
+PACKET_TYPE_SVC_MESSAGE = 'svc_message'
+PACKET_TYPE_NEW_CONNECTION = 'new_connection'
+
+DATA_TYPE_FILE_CHUNK = 'file_chunk'
+DATA_TYPE_CMD = 'cmd'
+DATA_TYPE_SEARCH_QUERY = 'search_query'
+DATA_TYPE_SEARCH_RESULT = 'search_result'
+DATA_TYPE_PEER_PUBKEY = 'peer_pubkey'
+
+SVC_MESSAGE_BAD_PACKET = 'bad_packet'
+SVC_MESSAGE_DECRYPT_ERROR = 'decrypt_error'
+SVC_MESSAGE_YOU_ARE_STRANGER = 'you_are_stranger'
+
+RECV_OK_CODE = 0
+RECV_ERROR_CODE = 1
+
+HEADER_SVC_YOU_ARE_STRANGER = {'type': PACKET_TYPE_SVC_MESSAGE, 'msg': SVC_MESSAGE_YOU_ARE_STRANGER}
+
+HEADER_RECV_OK = {'type': PACKET_TYPE_RECV_RESULT, 'code': RECV_OK_CODE}
+HEADER_RECV_ERROR = {'type': PACKET_TYPE_RECV_RESULT, 'code': RECV_ERROR_CODE}
+
+key = None
+
+peers = {}
+
+class Peer:
+    def __init__(self, peer_addr, pubkey):
+        self.addr = peer_addr
+        self.pubkey = pubkey
+
+def get_key():
+    global key
+    if not key:
+        key = simplecrypto.RsaKeypair()
+    return key
+
+def pickle_data(data):
+    return pickle.dumps(data, protocol=4)
+
+def write_svc_msg(fobj, svc_msg, extra_data={}):
+    MSG = {'type': PACKET_TYPE_SVC_MESSAGE, 'msg': svc_msg}
+    if extra_data:
+        MSG.update(extra_data)
+    fobj.write(pickle_data(MSG))
+
+class UDPRequestHandler(socketserver.DatagramRequestHandler):
+    def handle(self):
+        datagram = self.rfile.read(BUFSIZE)
+        if self.client_address not in peers:
+            write_svc_msg(self.wfile, SVC_MESSAGE_YOU_ARE_STRANGER)
+            return
+        try:
+            unpickled_datagram = pickle.dumps(datagram)
+        except pickle.UnpicklingError:
+            write_svc_msg(self.wfile, SVC_MESSAGE_BAD_PACKET)
+            return
+        pk = get_key()
+        try:
+            data = pickle.loads(pk.decrypt_raw(unpickled_datagram['packet']))
+        except:
+            write_svc_msg(self.wfile, SVC_MESSAGE_DECRYPT_ERROR, {'packet_id': unpickled_datagram['packet_id']})
+            return
+        block_id = data['block_id']
+        fragment_num = data['num']
+        cmd = data['']
+
+
+