CnE CTF 2024 - Crypto 01

I used this site to calculate the symmetry key:

https://www.irongeek.com/diffie-hellman.php?

Then I used Copilot to create the from hex script:

message = bytes.fromhex("c2efc4fae5b0e7e7b0b2dee9b2ededecb5efdef3f4b0b2f2fc") symmetric_key = 129 xored_message = bytes([b ^ symmetric_key for b in message]) print(xored_message.decode('utf-8', errors='ignore'))