<?php

include_once 'crypt.php';
$password = '******';
# can be genegated by crypt::rand()
$salt = 'the password salt';
# same
$key = crypt::pbkdf2($password, $salt);
# secret key
$message = 'secret message for humanity';
# message to hide
$encrypted = crypt::encrypt($message, $key);
# encrypt message, raw binary ciphertext returned
$decrypted = crypt::decrypt($encrypted, $key);
# decrypt the ciphertext, original variable returned
echo $decrypted;
# 'secret message for humanity'