diff --git a/tplink-smartplug.py b/tplink-smartplug.py
index 3a2fde8..40b4831 100644
--- a/tplink-smartplug.py
+++ b/tplink-smartplug.py
@@ -1,99 +1,115 @@
 #!/usr/bin/env python
-# 
+#
 # TP-Link Wi-Fi Smart Plug Protocol Client
 # For use with TP-Link HS-100 or HS-110
-#  
+#
 # by Lubomir Stroetmann
-# Copyright 2016 softScheck GmbH 
-# 
+# Copyright 2016 softScheck GmbH
+#
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
-# 
+#
 #      http://www.apache.org/licenses/LICENSE-2.0
-# 
+#
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-# 
+#
 #
 import socket
 import argparse
 
-version = 0.1
+version = 0.2
+
 
-# Check if IP is valid
 def validIP(ip):
-	try:
-		socket.inet_pton(socket.AF_INET, ip)
-	except socket.error:
-		parser.error("Invalid IP Address.")
-	return ip 
+    """Check if IP is valid"""
+    try:
+        socket.inet_pton(socket.AF_INET, ip)
+    except socket.error:
+        parser.error("Invalid IP Address.")
+    return ip
 
 # Predefined Smart Plug Commands
 # For a full list of commands, consult tplink_commands.txt
-commands = {'info'     : '{"system":{"get_sysinfo":{}}}',
-			'on'       : '{"system":{"set_relay_state":{"state":1}}}',
-			'off'      : '{"system":{"set_relay_state":{"state":0}}}',
-			'cloudinfo': '{"cnCloud":{"get_info":{}}}',
-			'wlanscan' : '{"netif":{"get_scaninfo":{"refresh":0}}}',
-			'time'     : '{"time":{"get_time":{}}}',
-			'schedule' : '{"schedule":{"get_rules":{}}}',
-			'countdown': '{"count_down":{"get_rules":{}}}',
-			'antitheft': '{"anti_theft":{"get_rules":{}}}',
-			'reboot'   : '{"system":{"reboot":{"delay":1}}}',
-			'reset'    : '{"system":{"reset":{"delay":1}}}'
-}
+commands = {'info': '{"system":{"get_sysinfo":{}}}',
+            'on': '{"system":{"set_relay_state":{"state":1}}}',
+            'off': '{"system":{"set_relay_state":{"state":0}}}',
+            'cloudinfo': '{"cnCloud":{"get_info":{}}}',
+            'wlanscan': '{"netif":{"get_scaninfo":{"refresh":0}}}',
+            'time': '{"time":{"get_time":{}}}',
+            'schedule': '{"schedule":{"get_rules":{}}}',
+            'countdown': '{"count_down":{"get_rules":{}}}',
+            'antitheft': '{"anti_theft":{"get_rules":{}}}',
+            'reboot': '{"system":{"reboot":{"delay":1}}}',
+            'reset': '{"system":{"reset":{"delay":1}}}'
+            }
 
 # Encryption and Decryption of TP-Link Smart Home Protocol
 # XOR Autokey Cipher with starting key = 171
+# def encrypt(string):
+#     key = 171
+#     result = "\0\0\0\0"
+#     for i in string:
+#         a = key ^ ord(i)
+#         key = a
+#         result += chr(a)
+#     return result
+
+
 def encrypt(string):
-	key = 171
-	result = "\0\0\0\0"
-	for i in string: 
-		a = key ^ ord(i)
-		key = a
-		result += chr(a)
-	return result
+    key = 171
+    result = b"\0\0\0" + bytes([len(string)])
+    for i in string.encode('latin-1'):
+        a = key ^ i
+        key = a
+        result += bytes([a])
+    return result
+
 
 def decrypt(string):
-	key = 171 
-	result = ""
-	for i in string: 
-		a = key ^ ord(i)
-		key = ord(i) 
-		result += chr(a)
-	return result
+    key = 171
+    result = b""
+    for i in string:
+        a = key ^ i
+        key = i
+        result += bytes([a])
+    return result.decode('latin-1')
 
 # Parse commandline arguments
-parser = argparse.ArgumentParser(description="TP-Link Wi-Fi Smart Plug Client v" + str(version))
-parser.add_argument("-t", "--target", metavar="<ip>", required=True, help="Target IP Address", type=validIP)
+parser = argparse.ArgumentParser(description="TP-Link Wi-Fi Smart Plug " +
+                                 "Client v" + str(version))
+parser.add_argument("-t", "--target", metavar="<ip>", required=True,
+                    help="Target IP Address", type=validIP)
 group = parser.add_mutually_exclusive_group(required=True)
-group.add_argument("-c", "--command", metavar="<command>", help="Preset command to send. Choices are: "+", ".join(commands), choices=commands) 
-group.add_argument("-j", "--json", metavar="<JSON string>", help="Full JSON string of command to send")
+group.add_argument("-c", "--command", metavar="<command>",
+                   help="Preset command to send. Choices are: " +
+                   ", ".join(commands), choices=commands)
+group.add_argument("-j", "--json", metavar="<JSON string>",
+                   help="Full JSON string of command to send")
 args = parser.parse_args()
 
 # Set target IP, port and command to send
 ip = args.target
 port = 9999
 if args.command is None:
-	cmd = args.json
+    cmd = args.json
 else:
-	cmd = commands[args.command]
+    cmd = commands[args.command]
 
+# Send command and receive reply
 
-
-# Send command and receive reply 
 try:
-	sock_tcp = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-	sock_tcp.connect((ip, port))
-	sock_tcp.send(encrypt(cmd))
-	data = sock_tcp.recv(2048)
-	sock_tcp.close()
-	
-	print "Sent:     ", cmd
-	print "Received: ", decrypt(data[4:])
+    sock_tcp = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    sock_tcp.connect((ip, port))
+    sock_tcp.send(encrypt(cmd))
+    data = sock_tcp.recv(2048)
+    sock_tcp.close()
+
+    print("Sent:     ", cmd)
+    print("Received: ", decrypt(data[4:]))
 except socket.error:
-	quit("Cound not connect to host " + ip + ":" + str(port))
+    quit("Cound not connect to host " + ip + ":" + str(port))