(In-)secure XOR Practice

Now it's time to break XOR.

XOR offers the perfect security, but we talked in the class that (if we use it in-securely) an adversary can break it.

Please proceed to the xor-is-perfect folder. You will find the following files after the ls command:

flag template.py xor-is-perfect

Please fix the template.py file. This file runs xor-is-perfect file, which

1. Gives you the ciphertext and plaintexts
2. Gives you another secret number (a secret message)
3. Wait for the plaintext message of the secret message

You are required to extract the key and decrypt the secret number you will get from the step 2. All this procedure is managed by template.py. Your job is to edit the file so that finally you can return the correct plaintext to xor-is-perfect file. Once you're successful, you will get the flag