[OverTheWire] Krypton Level 1

As Krypton is a much shorter game than Bandit, we will have already achieved a certain amount of progress at the end of this weekend.

The assignment of this level is:

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!

The previous level indicated that the following ones would be in the /krypton/ folder. So, first things first, we do:

cd /krypton/krypton1

The file krypton2, which the assignment mentioned, is right there, and there are no permission problems on our way, so we can just cat it.


Now what we know of this is that it is encrypted with a “simple rotation”. Rotation ciphers are ciphers that shift the alphabet forward or backwards by a certain amount of letters. The most famous of these is called ROT13 which, as the name suggests, rotates the alphabet by 13 letters. Note that, since the English alphabet contains 26 letters, and the rotation operation is modular, encrypting in ROT13 is the same thing as decrypting in ROT13. The generalised version of the algorithm is called ROT-n, and there is a handy online decrypter here.

You can decode this password with any online ROT13 decoder, including the one above, of course. It will give you:


Very straightforward (and punny, I must add). We can now continue our challenge.


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Self-taught in cyber security, currently working as a cyber attack and incident response analyst. Also have previous experience in cyber security / threat intelligence analysis. I look forward to eventually starting a career in penetration testing. Please contact me at alexanderclarke@altervista.org for any inquiries.

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