diff --git a/scripts/fake-registration-server.py b/scripts/fake-registration-server.py
index 9023b98..74417a1 100755
--- a/scripts/fake-registration-server.py
+++ b/scripts/fake-registration-server.py
@@ -27,8 +27,8 @@ signal.signal(signal.SIGINT, exit_cleanly)
 from Cryptodome.Cipher import AES
 pad = lambda s: s + (16 - len(s) % 16) * chr(16 - len(s) % 16)
 unpad = lambda s: s[:-ord(s[len(s) - 1:])]
-encrypt = lambda msg, key: AES.new(key.encode(), AES.MODE_ECB).encrypt(pad(msg).encode())
-decrypt = lambda msg, key: unpad(AES.new(key.encode(), AES.MODE_ECB).decrypt(msg.encode()))
+encrypt = lambda msg, key: AES.new(key, AES.MODE_ECB).encrypt(pad(msg).encode())
+decrypt = lambda msg, key: unpad(AES.new(key, AES.MODE_ECB).decrypt(msg)).decode()
 
 from base64 import b64encode
 import hashlib
@@ -84,7 +84,7 @@ class JSONHandler(tornado.web.RequestHandler):
 				't': ts,
 				'success': True }
 			answer = jsonstr(answer)
-			payload = b64encode(encrypt(answer, options.secKey)).decode()
+			payload = b64encode(encrypt(answer, options.secKey.encode())).decode()
 			signature = "result=%s||t=%d||%s" % (payload, ts, options.secKey)
 			signature = hashlib.md5(signature.encode()).hexdigest()[8:24]
 			answer = {
@@ -115,7 +115,7 @@ class JSONHandler(tornado.web.RequestHandler):
 		print(self.request.headers)
 		if payload:
 			try:
-				decrypted_payload = decrypt(binascii.unhexlify(payload), options.secKey).decode()
+				decrypted_payload = decrypt(binascii.unhexlify(payload), options.secKey.encode())
 				if decrypted_payload[0] != "{":
 					raise ValueError("payload is not JSON")
 				print("payload", decrypted_payload)
diff --git a/scripts/mq_pub_15.py b/scripts/mq_pub_15.py
index 3617169..ccb4311 100755
--- a/scripts/mq_pub_15.py
+++ b/scripts/mq_pub_15.py
@@ -21,15 +21,15 @@ iot:
 from Cryptodome.Cipher import AES
 pad = lambda s: s + (16 - len(s) % 16) * chr(16 - len(s) % 16)
 unpad = lambda s: s[:-ord(s[len(s) - 1:])]
-encrypt = lambda msg, key: AES.new(key.encode(), AES.MODE_ECB).encrypt(pad(msg).encode())
-decrypt = lambda msg, key: unpad(AES.new(key.encode(), AES.MODE_ECB).decrypt(msg.encode()))
+encrypt = lambda msg, key: AES.new(key, AES.MODE_ECB).encrypt(pad(msg).encode())
+decrypt = lambda msg, key: unpad(AES.new(key, AES.MODE_ECB).decrypt(msg)).decode()
 
 def iot_dec(message, local_key):
-	message_clear = decrypt(base64.b64decode(message[19:]), local_key)
+	message_clear = decrypt(base64.b64decode(message[19:]), local_key.encode())
 	print (message_clear)
 	return message_clear
 def iot_enc(message, local_key, protocol):
-	messge_enc = encrypt(message, local_key)
+	messge_enc = encrypt(message, local_key.encode())
 	if protocol == "2.1":
 		messge_enc = base64.b64encode(messge_enc)
 		signature = b'data=' + messge_enc + b'||pv=' + protocol.encode() + b'||' + local_key.encode()
diff --git a/scripts/tuya-discovery.py b/scripts/tuya-discovery.py
index 9d0981c..b196020 100755
--- a/scripts/tuya-discovery.py
+++ b/scripts/tuya-discovery.py
@@ -12,8 +12,8 @@ import json
 from Cryptodome.Cipher import AES
 pad = lambda s: s + (16 - len(s) % 16) * chr(16 - len(s) % 16)
 unpad = lambda s: s[:-ord(s[len(s) - 1:])]
-encrypt = lambda msg, key: AES.new(key.encode(), AES.MODE_ECB).encrypt(pad(msg).encode())
-decrypt = lambda msg, key: unpad(AES.new(key.encode(), AES.MODE_ECB).decrypt(msg.encode()))
+encrypt = lambda msg, key: AES.new(key, AES.MODE_ECB).encrypt(pad(msg).encode())
+decrypt = lambda msg, key: unpad(AES.new(key, AES.MODE_ECB).decrypt(msg)).decode()
 
 from hashlib import md5
 udpkey = md5(b"yGAdlopoPVldABfn").digest()