Ulli Weichert/ April 3, 2022/ IT-Security, Write-Ups/ 0Kommentare

rail-fence

Description

A type of transposition cipher is the rail fence cipher, which is described here. Here is one such cipher encrypted using the rail fence with 4 rails. Can you decrypt it?
Download the message here.
Put the decoded message in the picoCTF flag format, picoCTF{decoded_message}.

Solving

So - there is everything we need to know in the challenge task description.

1. Go to Cyberchef.io

2. Search for rail-fence in the operations windows and take these settings:

   key: 4 - offset: 0

3. Paste the text from the message.txt

4. And finally - get your flag