~ Level 11→12 ~
Level Description
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
Grep, sort, uniq, strings, base64, tr, tar, gzip, bzip2, and xxd are all commands that may be used to solve the current level.
OverTheWire provides a link for this level as well, this time giving information on something called rot13
.
Research Before Solving
Looking at the linked article, rot13 is a method of encryption that uses letter substitution. A letter is replaced with the letter in the alphabet that comes 13 places after it. Wikipedia further states that while rot13 is a method of encryption, it is considered to be a very weak form. No further information that may help us is provided in the article.
Let's look at potential commands for further help. The first in the given list that we have not worked with is the
tr command. Documentation for this command states that it is used to
translate standard input to standard output
. Translation sounds like something which may be helpful, let's look at
search engine results to see more.
Multiple sources, when searching for tr rot13
, advise how to perfrom a rot13 translation. In order to do so
we need to cat the file we wish to translate and pipe the results into a tr command
with the following rules appended [A-Za-z] [N-ZA-Mn-za-m]
Solution Walkthrough
Log in as bandit11 with the appropriate password. Once logged in, we can use ls to see what files are in the home directory.

We can go ahead and run our command since we have immediate access to the file where the password is located: cat data.txt | tr [A-Za-z] [N-ZA-Mn-za-m]

Now that we've found the password to the next level, 5Te8Y4drgCRfCx8ugdwuEX8KFC6k2EUu, we are ready to move on!