Question

I have a bit of a unique problem with an upcoming project; I need an algorithm that can take non-plaintext data from a variable and decrypt it as fast as possible. However, I use decrypt in the loosest possible sense of the word, because what I am looking for is a simple, optimized algorithm in which the sole objective is fast decryption. The complexity/difficulty of decrypting the said string is unimportant; For these purposes, a string with all of its characters shifted by one bit would be every bit as effective as an AES implementation.
I understand I could simply iterate through “encrypted” string and shift all of its characters, but I’m curious as to if there’s a faster way to achieve this. I was considering caching, but I’m unsure if this script would be able to write files, so that complicates matters. Also, please note, I would NOT be able to install a plugin/extension (not even PECL), so this must be purely PHP.

Answer 1

You could use str_rot13() – It’s extremely simple but it’s native PHP.