Bijective is a library that can compute pairings between alphanumeric strings, and integers. Every integer can be mapped to an alphanumeric string, and every alphanumeric string can be mapped back to an integer with zero unpaired permutations.
$ git clone git@github.com:unfunco/bijective.git
$ cd bijective/ext/bijective
$ phpize
$ ./configure
$ make
$ make install
Copyright © 2013 Daniel Morris
Made available under the terms of the Apache License, Version 2.0.