Encrypt Data
(Appendix C, Cryptography - Pg 101)
<?php
$crypt = new crypt();
$crypt->cleartext = '1234567890123456';
$crypt->generate_iv();
$crypt->encrypt();
$ciphertext = $crypt->ciphertext;
$iv = $crypt->iv;
$string = base64_encode($iv . $ciphertext);
/* Store $string. */
?>