Instead of compressing our data, we could encrypt it or
even do both. Encryption can easily be achieved using
the mcrypt extension which has been available in PHP
since PHP 3, but really only became powerful in PHP 4.
I really want to recommend that you read more about
cryptography before you start using it in your software.
It’s best to understand why you do something a certain
way than to just assume that it will be secure enough,
when following the instructions I give below.