Talk:Cryptography/Atbash cipher

The article reads: "Effectively Ashbat is the 26th Caesar shift."

Sorry, this is not the case. I'd even say this is wrong. The 26th shift would be the same as ROT26, which results in mapping A=A, B=B, ... the ID-function. If we decode A=1, B=2, ... Z=26, then Atbash (and not "ash bat", the phoenix bat which burns itself at midnight and arises from its ashes) rather computes as f(x) = 27 - x, while a caesar substituion is f(x) = n + x for an arbitrary n (cyclically mapping any overflows to [1..26], like in f(x) = ((n + x - 1) mod 26) + 1)