How to encrypt php source code under Yii Framework

I have developed a php web project with the framework of Yii. We need to encrypt the source code. Does anyone succeed to encrypt php source code under Yii framework? Please kind give me some idea of you know how to do it. Thanks a lot.

Have you tried Zend guard?

http://www.zend.com/en/products/guard/

An alternative http://www.ioncube.com/sa_encoder.php

Remember this http://www.yiiframework.com/license/