xor.py

#!/usr/bin/python
# -*- coding: UTF-8 -*-


string = "something something something"
key = "cheese"

def crypt(string, key):
    data = ''
    for i in range(len(string)):
        # XOR
        xc = ord(string[i]) ^ ord(key[i%len(key)])
        # Convert XOR to base 2
        xc = bin(xc)[2:].zfill(8)
        data += str( xc )

        #print string[i]
    return data

def decrypt(string, key):
    data = ''
    for i in range( (len(string)+1) / 8):
        # Convert each 8 bits to base 10
        x = int(  string[((i+1)*8)-8:(i+1)*8], 2  )
        # XOR with key
        data += chr(  x ^ ord(key[i%len(key)])  )
    return data

print "String: %s - Key: %s \n \n%s\n" % (string, key, "="*10)

x = crypt(string, key)
print x + "\n"

y= decrypt(x, key)
print y + "\n"