Krypton Level 1 → Level 2

Level Info

The password for level 2 is in the file ‘krypton2’. It is ‘encrypted’ using a simple rotation. It is also in non-standard ciphertext format. When using alpha characters for cipher text it is normal to group the letters into 5 letter clusters, regardless of word boundaries. This helps obfuscate any patterns. This file has kept the plain text word boundaries and carried them to the cipher text. Enjoy!

First, we need to find this ‘krypton2’ file. Using find, we see 1 files (-type f) with the same name (-name).

find / -type f -name krypton2 2</dev/null
/games/krypton/krypton1/krypton2

cat /games/krypton/krypton1/krypton2
YRIRY GJB CNFFJBEQ EBGGRA

Another clue is that this cipher is encrypted using a simple rotation. The most notable rotation cipher is rot13. So I wrote a simple bash script to implement rot13 to test a rotation cipher and intended to use it to check all rotation possibility. Little did I know that rot13 is the correct answer.

#!/bin/bash

cipher=$(</games/krypton/krypton1/krypton2)
alpha=ABCDEFGHIJKLMNOPQRSTUVWXYZ
echo $alpha
echo $cipher

fst=${alpha:0:13}
snd=${alpha:13}
rot=$snd$fst

echo $rot
echo $cipher | tr $alpha $rot

The output give us the correct password for level two.

LEVEL TWO PASSWORD ROTTEN

Additional Reference: