- hex2bin: documentation ( source)
- base64_decode: documentation ( source)
- strrev: documentation ( source)
<?php
$secret = "3d3d516343746d4d6d6c315669563362";
//bin2hex(strrev(base64_encode($secret)));
$secret1 = hex2bin($secret);
$secret2 = strrev($secret1);
$secret3 = base64_decode($secret2);
print $secret3;
?>