\> PicoCTF 2022 Writeups

This website contains Jackwin Hui's writeups for the 2022 PicoCTF competition.

PicoCTF2022 - Vigenere

Description

Can you decrypt this message? Decrypt this message using this key "CYLAB".

Information

Point Value: 100 points

Category: Cryptography

Hints

  1. https://en.wikipedia.org/wiki/Vigen%C3%A8re_cipher

Solution

We know the text file is encoded using a vigenere cipher, so we open the txt file to obtain the encoded cipher, and use CyberChef to decode it. Entering the encoded cipher from the txt file as the input and using the "Vigenere Decode" recipe with a key of "CYLAB", we get the output "picoCTF{D0NT_US3_V1G3N3R3_C1PH3R_ae82272q}".

Flag

picoCTF{D0NT_US3_V1G3N3R3_C1PH3R_ae82272q}