static function decrypt($string, $key)
{
$result = '';
$string = base64_decode($string);
for ($i = 0; $i < strlen($string); $i++) {
$char = substr($string, $i, 1);
$keychar = substr($key, $i % strlen($key) - 1, 1);
$char = chr(ord($char) - ord($keychar));
$result .= $char;
}
return Toolbox::unclean_cross_side_scripting_deep($result);
}