php mcryptの暗号化と復号化の小さな例

/**
* mcrypt 暗号化と復号化
* by bbs.it-home.org
*/
$data = 'data';
$key = "key";
$algorithm = MCRYPT_BLOWFISH;
$mode = MCRYPT_MODE_CBC;
$iv = mcrypt_create_iv(mcrypt_get_iv_size($algorithm,$mode), MCRYPT_DEV_URANDOM);
$encrypted_data = mcrypt_encrypt($algorithm, $key, $data , $mode, $iv);
$decrypted_data = mcrypt_decrypt($algorithm, $key, $encrypted_data, $mode, $iv);
print "解密データは：$decrypted_data";
?>