Base64 enocde all POST requests

Hey DPers,
I've got a problem here and I need your help.

I was wondering if there is any way to encode (via base64) all of the POST values (but not titles) so that a code like the following will output the origional non-encoded value.

<?php
echo base64_decode($_POST['xyz']);
?>

Code (markup):

Thank you.

 

Could you loop through the post values and do it, say:

foreach($_POST as $P){
base64_decode($P);
}