Python: Two-way Alphanumeric Encryption

Question

I am using Python 2.7. I have an alphanumeric string, on which I want to perform a encryption/decryption. Whatever I do should remain 2-way and the result shoul

Answer 1

If you want serious encryption (read unbreakable) then I'd use AES from pycrypto something like this.

>>> from Crypto.Cipher import AES
>>> from Crypto import Random
>>> key = b'Sixteen byte key'
>>> iv = Random.new().read(AES.block_size)
>>> cipher = AES.new(key, AES.MODE_CFB, iv)
>>> msg = iv + cipher.encrypt(b'Attack at dawn')
>>> msg.encode("hex")
'e10e096aabff9db382abe8d704404995a7b64d72a4e1b9e5208912d206c4'

That is your ascii message. Now decode the message like this

>>> recv='e10e096aabff9db382abe8d704404995a7b64d72a4e1b9e5208912d206c4'
>>> cipher.decrypt(recv.decode("hex"))[len(iv):]
'Attack at dawn'
>>> 

Any encryption method you make up yourself will be easily breakable by an expert and the one you've shown above falls into that category.