encryption – How to encrypt whole website source code which made in CodeIgniter framework? Is this possible to encrypt whole website source code for the security

Developing a application in CodeIgniter framework. Project requirement is that after development is over all the source code should be encrypted. How to achieve this and when need modification how to decrypt it so can modification can be done. This is done for the security purpose and which is the best secure method?

output should be like = XcB66ijatBSzzBrYubtxozKlLNA3LfjP9mXBxIVU8b7Zd5gwasR7LeMRrUVZn/Ra4/4tp/

source code :

<?php

class Upload extends CI_Controller {

        public function __construct()
        {
                parent::__construct();
                $this->load->helper(array('form', 'url'));
        }

        public function index()
        {
                $this->load->view('upload_form', array('error' => ' ' ));
        }

        public function do_upload()
        {
                $config('upload_path')          = './uploads/';
                $config('allowed_types')        = 'gif|jpg|png';
                $config('max_size')             = 100;
                $config('max_width')            = 1024;
                $config('max_height')           = 768;

                $this->load->library('upload', $config);

                if ( ! $this->upload->do_upload('userfile'))
                {
                        $error = array('error' => $this->upload->display_errors());

                        $this->load->view('upload_form', $error);
                }
                else
                {
                        $data = array('upload_data' => $this->upload->data());

                        $this->load->view('upload_success', $data);
                }
        }
}
?>