Krypton Level 1 → Level 2

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1. 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!

2. Understand the challenge text

The level description tells you several important things:

“The password for level 2 is in the file krypton2. It is ‘encrypted’ using a simple rotation.”

Key hints:

• “simple rotation” → this strongly suggests a ROT cipher

• Alphabet-only cipher

• Word boundaries are preserved (spaces are real spaces)

This almost always means ROT13 unless stated otherwise.

3. Log in to Krypton Level 1

ssh [email protected] -p 2231

Password (from previous level):

KRYPTONISGREAT

4. Locate the level file

Once logged in:

krypton1@krypton:~$ cd /krypton/krypton1
krypton1@krypton:/krypton/krypton1$ ls
krypton2  README
krypton1@krypton:/krypton/krypton1$

You’ll see:

krypton2

View its contents:

krypton1@krypton:/krypton/krypton1$ cat krypton2

You should see something similar to:

YRIRY GJB CNFFJBEQ EBGGRA

5. Identify the cipher (ROT13)

ROT13 properties:

• Each letter is shifted 13 positions

• A ↔ N, B ↔ O, C ↔ P, etc.

• Applying ROT13 twice returns the original text

• Very common in beginner cryptography challenges

Example:

A → NN → A

The structure and readability strongly confirm ROT13.

6. Decode using ROT13 (command line)

Run:

krypton1@krypton:/krypton/krypton1$ cat krypton2 | tr 'A-Za-z' 'N-ZA-Mn-za-m'

or

krypton1@krypton:/krypton/krypton1$ cat krypton2 | tr 'A-Z' 'N-ZA-M'

Output:

LEVEL TWO PASSWORD ROTTEN

7. Extract the password

From the decoded text:

LEVEL TWO PASSWORD ROTTEN

The password for krypton2 is:

ROTTEN

8. Log in to Level 2

ssh [email protected] -p 2231

Password:

ROTTEN

9. Why this level matters

This level teaches you to:

• Recognize ROT ciphers by pattern

• Understand that “encryption” may just be obfuscation

• Use simple UNIX tools (tr) for cryptanalysis

• Trust hints in challenge descriptions

ROT13 offers zero security—it only hides text from casual viewing.

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Keywords

ROT13, Caesar cipher, rotation cipher, substitution cipher, cryptography, cryptanalysis, plaintext, ciphertext, alphabet shift, frequency analysis, obfuscation, classical ciphers, OverTheWire, Krypton, CTF, Linux tools, tr command, SSH, puzzle, security, nerd cafe , نرد کافه

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