Bandit Level 11 -> Level 12

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

Commands you may need to solve this level

grep, sort, uniq, strings, base64, tr, tar, gzip, bzip2, xxd

• `tr` is used to translate or delete characters from the input text.

Helpful Reading Material

• Rot13 on Wikipedia

 

Write up

bandit11@bandit:~$ ls
data.txt
bandit11@bandit:~$ cat data.txt
Gur cnffjbeq vf 7k16JArUVv5LxVuJfsSVdbbtaHGlw9D4

 

There is a file encoded in ROT13, which replaces each letter with the 13th letter after it in the alphabet. When we use the `cat` command to view its content, it shows an unreadable combination of strings, similar to the previous challenge.

 

 

By checking the ROT13 Wikipedia page, we find a way to implement ROT13 using the `tr` command. The expression 'A-Za-z' 'N-ZA-Mn-za-m' maps uppercase letters A-Z to N-ZA-M, and lowercase letters similarly. Reversing this code will rerotate it back to the original text.

 

bandit11@bandit:~$ cat data.txt | tr 'N-ZA-Mn-za-m' 'A-Za-z'
The password is 7x16WNeHIi5YkIhWsfFIqoognUTyj9Q4

 

By relocating both uppercase and lowercase letters, we can finally retrieve the password!

 

 

Next Level : Level 12 -> 13