This is one of my writeups for PicoCTF 2018
My buddy Blaise told me he learned about this cool cipher invented by a guy also named Blaise! Can you figure out what it says? Connect with
nc 2018shell3.picoctf.com 59396.
- There are tools that make this easy.
- This cipher was NOT invented by Pascal
This task, like the first warmup task, involves deciphering text encrypted with the Vigenere Cipher - the cipher being indicated by the hints. But this time we don't have the key.
The Wikipedia page gives us the method : it consist of guessing they key length by observing repetitions in the ciphertext, then solving n caesar ciphers (where n is the length of the key).
I used an online tool to do that. The
flag and the flag is in the middle of the plaintext :