https://github.com/JulesDT/ctfWriteUps/tree/master/Qiwi-Infosec%20%20CTF%202016/Crypto%20400_1

Original writeup (https://github.com/JulesDT/ctfWriteUps/tree/master/Qiwi-Infosec%20%20CTF%202016/Crypto%20400_1).