The Indecipherable Cipher
Description
CTF: Whitehacks 2022
Author: WickedEye (Ying Keat)
Difficulty: Easy
Some say this cipher cannot be deciphered. Well, do you believe them?
Even worse, some say this cipher is misattributed!
I would say that the key to solving this challenge is to remember who the true inventor was.
cipher.txt
Solution
Pwned by @skytect (opens in a new tab)
CP2022{j1b3n3e3_15_Pcn_Xa3f@x_K1dC3R_0A_yB3F01Ys}
Looking at the ciphertext, one can see that it's some form of cipher that substitutes letters. Immediately, one thinks of ROT13 (opens in a new tab) and the Vignère cipher (opens in a new tab).
some say this cipher is misattributed!
The Vignère cipher just happens to be misattributed! However, the cipher requires a key which is hard to guess with just the cryptic ciphertext.
I would say that the key to solving this challenge is to remember who the true inventor was.
From the Wikipedia site (opens in a new tab), we can find that the first guy who came up with the cipher is Giovan Battista Bellaso.
If we try to decrypt it on CyberChef (opens in a new tab) with
the key GIOVAN, it works!
WH2022{v1g3n3r3_15_Juz_Ca3s@r_C1pH3R_0N_sT3R01Ds}