zendframework/zf2 — pull request #1589 by ezimuel (2012-06-25 13:36:25+00:00)
Title: Fixed the bcrypt using $2y$ syntax for PHP 5.3.7+

Starting from PHP 5.3.7 the bcrypt implementation in crypt() should use the $2y$ syntax instead of $2a$. There was a security issue with password contains 8-bit characters for some specific environments.
More information here:
http://php.net/security/crypt_blowfish.php
http://en.wikipedia.org/wiki/Crypt_%28Unix%29#Blowfish-based_scheme