4FoldCipher

Incognito 6.0

Challenge Overview

This crypto challange seems to be weird we look at it at first. The first thing I tried was concatenating all digits and removing / to get some binary text. Nothing happened.

Given ciphertext

00 0001 000 101 010 1001 / 011010 1000 01 000 0000 / 0000 010 / 0000 010 000 110 / 00001 01111 11 11111 111 1000 1011 00001 1011 / 0000 010 / 1 1100 111 001 / 0001 000 110

Steps

1. Binary → Morse Code

I noticed a possible Morse pattern where 0 = "." and 1 = "-". The / symbols separate words, just like in Morse. After converting:

.. ...- ... -.- .-. -..- / .--.-. -... .- ... .... / .... .-. / .... .-. ... --. / ....- .---- -- ----- --- -... -.-- ....- -.-- / .... .-. / - --.. --- ..- / ...- ... --.

Using a Morse translator, this gives:

IVSKRX@BASHHRHRSG41M0OBY4YHRTZOUVSG

2. Decrypt the String

After many tries I managed to find the correct decryption method

reverse, atbash cipher

After many tries, I happened to find that by Reversing the string and applying the Atbash Cipher, the result becomes:

THEFLAGISB4BYL0N14THISISSHZY@CIPHER

Final Flag

ictf{B4BYL0N14}

made by k0d