How do you decrypt a ROT13 encryption on the terminal itself

Question

I'm working on a project that involves basic encryption techniques, and I encountered a file encrypted using ROT13. I understand that ROT13 is a simple Caesar cipher, where each letter is shifted by 13 positions in the alphabet. However, I want to decrypt this directly on the terminal rather than writing a Python or other script.

Is there a command-line tool that supports ROT13 decryption natively? If so, how can I use it to decrypt the file or string? Any guidance on efficient ways to achieve this would be helpful!

Answer 1

Yes, it's possible to decrypt a ROT13 encrypted file/string directly in the terminal.

ROT13 is a simple encryption method where each letter is replaced by the letter 13 positions ahead in the alphabet. Since the alphabet has 26 letters, applying ROT13 twice returns the original text.

For this, we can use the built-in tr command.

1. This is how we decrypt an ROT13 encrypted string:

This command translates each letter accordingly and prints the output "Hello World".

2. Suppose you have a ROT13 encrypted file like this:

This can be easily decrypted using the below command:

This command translates each letter in the file accordingly and prints the output "Hello World".

3. Another way to decrypt an ROT13 encrypted file is using tools like rot13 which might be available in your package manager.

Comments

Great explanation! I’m curious—can the tr command handle more complex substitutions or is it just for simple character mappings like ROT13?