ec2-3-228-220-31.compute-1.amazonaws.com | ToothyWiki | RecentChanges | Login | Webcomic A [shift cipher]. It is not intended to be a serious cipher - since it is easy to break - but it is commonly employed in newsgroups to hide things like spoilers and puzzle solutions. Each letter is moved on 13 places in the alphabet. It has the special property that applying it twice reveals the original plaintext.
Like DES? 2ROT13 is insecure. Unlike DES? 3ROT13 is no more secure than bogstandard ROT13.
How should ROT13 cope with accented letters? What about greek and cyrillic (or alphabets from still further afield?)
Same way it does with upper an lower case ASCII, I assume, split the set into regions of 13 and rotate within them. How does UseNet? rotting cope with, say, numbers? --Vitenka
Just ignore everything that isn't in the latin alphabet, leaving it as-is. - MoonShadow
Not to be confused with the CaesarCipher?, which is a ShiftCipher? that steps each letter 3 places forward in the alphabet.