Level11

Level Goal

The password for the next level is stored in the file data.txt, where all lowercase (a-z) and uppercase (A-Z) letters have been rotated by 13 positions.

Solution

Rot13 is a shift cipher where each letter of the message is shifted by 13 places for encoding/decoding the message. The tr utility is used for translating or deleting characters, so we can use it to decode the given rot13 cipher by translating each character in the message from it’s place in the first set [a-zA-Z] to it’s place in the second set [n-za-mN-ZA-M]. See the tr man page for further reading.