ROT Util

The ROT Util is a simple program that enables you to encrypt or decrypt ROT text. It will convert to and from ROT levels 1 to 26 and also has a built in “AutoROT” feature which attempts to automatically work out what ROT level encoded text was ciphered with, based on a wordlist.

I wrote it because at the time I hadn’t found any programs that had an automatic decoding option. Outlook Express has a built in “Decode from ROT13” function for email and newsgroups but you can’t encode at all, or decode any other ROT levels than 13.

ROT (’rotate alphabet’) is another name for the Caesar Cipher, used by Julius Caesar to communicate with his army. Caesar is considered to have been one of the first people to use encryption to send messages. Ironically this method is still used by many to send messages across the Internet over a thousand years later. The algorithm works by shifting each letter in the input message, thus is a shift cipher.

A sample of ROTated text:

This is text rotated to 13 places
--> ROT13 -->
Guvf vf grkg ebgngrq gb 13 cynprf

Without some sort of utility to “decode” this text it would be impossible to read what it said. Also highlighted by the above example is the fact that only alpha characters are rotated. Numbers, punctuation and special characters aren’t rotated, and therefore can still be seen after your text has been encoded.

The program comes with a feature to automatically decode rotated text. It does this by using a list of words, which can be edited by the end user. The text is rotated through 1 to 26 times and given a score based on how many matches there were with the wordlist. The text with the highest score is presented as the ‘best’ decoded option.

Whilst more advanced language analysis is possible the program manages to accurately identify most decoded text when given a list of the 250 most common English words, which is available to download below.

The files available for this release are below.

• The Ceasar Shift on Pookey’s site.