Encrypting plugin

Hi all
I have a plugin that is encrypted and I want to do the same for a plugin we developed. How can I do the same as this plugin?
Thanks

<?php
/*
Plugin Name: XXXXX
Plugin URI: XXXXX
Description: XXXXX
Version: XXXXXX
Author: XXXXX
Author URI: XXXXX
*/
$slk_evc='CODE HERE';$slk_dvc='CODE HERE';$slk_file=__FILE__;eval(base64_decode($slk_dvc));
return;?>
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

Oh please, thats not encrypted. Its a waste of time. First off the means of decrypting the contents is sent with the code itself, located in the same file as the code. Would only take half a brain to rebuild it.