There is an issue on Yii2 to redirecting / urls to /frontend/web.
In other words we need a way to hidden /frontend/web from addresses.
We will do this without changing Apache configuration and creating virtual host or setting document root (It's good for share hostings that we have not access to apache.conf)
To extend the functionality of you web application relative to your requirements you are supposed to use existing yii core libraries or use external libraries. There are some steps to ensure security, uniqueness, modularity, performance and to avoid rework in future.
Update: This wiki has been rewritten to be in line with Yii 1.1.14. Since many of the detailed complexities are now handled by Yii, the article focuses on how the crypt() built-in function works and why it's important to use it correctly.
I installed phpseclib because I needed to do some AES encryption in my project. After all the hassle of installing php lib, I found out that Yii already has a security module (securityManager). I finally decided to keep using phpseclib because it has one big advantage over Yii securityManager module, it does not requite mcrypt to be installed in the phpserver!