Login System with Codeigniter [closed]
If you want to know about the libraries available for login/logout and more than you should read this:
How should I choose an authentication library for CodeIgniter?
and if you just simply want to understand a secure & simple login process then you should go and read the code for this one:
I would recommend ion auth: http://benedmunds.com/ion_auth/
it has great documentation, you could have several types for users,and that you could easily have admin group.