Krypton · OverTheWire

Krypton Level 1 → Level 2

Level 1

Username : krypton1

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 ciphertext. Enjoy!


To solve this level, we first ssh into the krypton1 server using the credentials provided above.

Screenshot from 2017-07-20 13-07-48.png

As the level information mentioned that the encryption is a simple rotation, my first impression was to try the ROT13 cipher. ROT13 (“rotate by 13 places”, sometimes hyphenated ROT-13) is a simple letter substitution cipher that replaces a letter with the letter 13 letters after it in the alphabet. ROT13 is a special case of the Caesar cipher, developed in ancient Rome. For more information on ROT13, read this page.

To solve this, I am going to utilize the ” tr ” command to implement a ROT13 cipher. Therefore, “A” would map to “N” and “Z” would map to “M”. The mapping for lower-case alphabets would be similar.

Screenshot from 2017-07-20 13-09-08.png

As we can see in the image above, the password for the next level is ” ROTTEN “. If the password wasn’t a ROT13 cipher, we would have tried other ROTn substitution ciphers to find the password.

Level 2

Username : krypton2
Password : ROTTEN
SSH : 

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