IrrORversible

Writeup for IrrORversible (Warmup) - 1337UP LIVE CTF (2024) 💜

Video walkthrough

Challenge Description

So reversible it's practically irreversible

Solution

Players can enter some text to encrypt.

As the challenge name hints, we should try some XOR operations.

Since XOR is reversible, having any two pieces of information will enable the recovery of the missing component, e.g. plaintext + key = ciphertext, ciphertext + key = plaintext, plaintext + ciphertext = key.

Note that the key is quite long, so you need to enter a sufficiently sized plaintext to recover it all.

Flag: INTIGRITI{b451c_x0r_wh47?}