Fady didn’t understand well the difference between encryption and encoding, so instead of encrypting some secret message to pass to his friend, he encoded it!
Hint: Fady’s encoding doens’t handly any special character
The input file is a set of words
ONE. Further analysis shows that it is a Base64-encoded Morse code. Let’s put this knowledge in a script:
1 2 3 4 5 6 7 8 9 10 11 12 from pwn import * import morse_talk as mtalk with open('zero_one', 'r') as f: data = f.read().translate(None, ' \n') data = data.replace("ZERO","0").replace("ONE","1") data = b64d(''.join(chr(int(data[i:i+8], 2)) for i in xrange(0, len(data), 8))) data = mtalk.decode(data) print data
When we run the script we get the flag:
1 2 $ python solve.py ALEXCTFTH15O1SO5UP3RO5ECR3TOTXT
Because Morse code does not handle special characters we have to fiddle with the flag a bit more. Here is the final version: