OverTheWire Krypton Level 1 → 2 tutorial!!

Login

Log in as krypton1 using the password from Level 0 → 1.

ssh krypton1@krypton.labs.overthewire.org -p 2231
# password: KRYPTONISGREAT

Why? Each Krypton level is a separate UNIX user. To solve 1 → 2, you must be the krypton1 user.

Task

The password for level 2 is in the file krypton2. It is encrypted using a simple rotation cipher (ROT13) and grouped into blocks of 5 letters to obfuscate word boundaries.

A little bit of Theory

• ROT13 is a Caesar cipher with shift = 13.
• It is symmetric: ROT13(ROT13(text)) = text.
• Common in forums to obfuscate spoilers or answers.

Further reading:

• ROT13
• Caesar Cipher

Solution

1. Navigate into the directory

   cd /krypton/krypton1
   ls
   cat README
   

   Why? Reading README confirms the encryption method (ROT13) and shows where the file containing the password (krypton2) is located.

   

   → Instructions confirm the cipher is ROT13.

2. Check the file krypton2

   cat krypton2
   

   Why? Inspecting the file reveals the actual ciphertext, grouped into blocks of 5 characters for obfuscation.

   Example content:

   YRIRY GJB CNFFJBEQ EBGGRA
   

   

3. Decrypt using tr

   cat krypton2 | tr 'A-Za-z' 'N-ZA-Mn-za-m'
   

   Why? The tr command maps letters 13 positions forward/backward, effectively performing ROT13 decryption.

   → Result:

   LEVEL TWO PASSWORD ROTTEN
   

   

4. Log into the next level

   ssh krypton2@krypton.labs.overthewire.org -p 2231
   # password: ROTTEN
   

Password

ROTTEN

Troubleshooting

• Wrong result? → Make sure you used the correct tr command (upper & lower case included).
• Extra spaces/newlines → Carefully copy only the password.
• Still confused? → Try an online tool like Cryptii ROT13.

Copy-paste quick run

ssh krypton1@krypton.labs.overthewire.org -p 2231
# password: KRYPTONISGREAT

cd /krypton/krypton1
cat krypton2 | tr 'A-Za-z' 'N-ZA-Mn-za-m'
# → LEVEL TWO PASSWORD ROTTEN

ssh krypton2@krypton.labs.overthewire.org -p 2231
# password: ROTTEN

Congrats 🎉 You solved Krypton Level 1 → 2 using ROT13 — welcome to krypton2!

Thanks for reading!

Until next time — Otsumachi!! 💖☄️✨