Encryption.php

<?php

function url_encrypt($string)
{
	$encrypt_method = "AES-256-CBC";
	$secret_key = 'ZwZSUU50OW2doUTXNHSUNYaGZOWUwQ0c3Z2doUwQ0cNYUU3ZUT09SNHX5wZSUaG9';
	$secret_iv = 'Zw0c3Z2d0OW2doUTXNoUwQ0cNYUU3ZUT09SU5HSUUwQUaG9NYaGNHX5wZSZSUZOWZw0c3Z2d5wZSZSUZOWoUwQ0cN0OWYUU3ZUT09SU5HSUUwQUaG2doUTXN9NYaGNHX';

	// hash
	$key = hash('sha256', $secret_key);

	$iv = substr(hash('sha256', $secret_iv), 0, 16);

	return base64_encode(openssl_encrypt($string, $encrypt_method, $key, 0, $iv));
}

function url_decrypt($enc_string)
{
	$encrypt_method = "AES-256-CBC";
	$secret_key = 'ZwZSUU50OW2doUTXNHSUNYaGZOWUwQ0c3Z2doUwQ0cNYUU3ZUT09SNHX5wZSUaG9';
	$secret_iv = 'Zw0c3Z2d0OW2doUTXNoUwQ0cNYUU3ZUT09SU5HSUUwQUaG9NYaGNHX5wZSZSUZOWZw0c3Z2d5wZSZSUZOWoUwQ0cN0OWYUU3ZUT09SU5HSUUwQUaG2doUTXN9NYaGNHX';

	// hash
	$key = hash('sha256', $secret_key);

	$iv = substr(hash('sha256', $secret_iv), 0, 16);

	return openssl_decrypt(base64_decode($enc_string), $encrypt_method, $key, 0, $iv);
}

function encode5t($str, $inLoop = true)
{
    if ($inLoop) {
        for ($i=0; $i<5; $i++) {
            $str = encode5t($str, false);
        }
        return $str;
    }
    return strrev(base64_encode($str));
}

function decode5t($str, $inLoop = true)
{
    if ($inLoop) {
        for ($i=0; $i<5; $i++) {
            $str = decode5t($str, false);
        }
        return $str;
    }
    return base64_decode(strrev($str));
}