kohana/core — pull request #462 by sarciszewski (2014-02-19 19:35:23+00:00)
Title: Update Encrypt.php

Read this please:
http://phpsecurity.readthedocs.org/en/latest/Insufficient-Entropy-For-Random-Values.html

Also, this should probably be wrapped inside of an authentication mechanism (Encrypt-then-HMAC) if it isn't already employed elsewhere.