<?xml version="1.0" encoding="ISO-8859-1"?>
<slide>
	<title>Hash Example</title>

	<example fontsize="1.7em"><![CDATA[<?php
define('SECRETKEY', 'quis custodiet ipsos custodes');

if (isset($_COOKIE['stamp'])) {
	if ($_COOKIE['stamp'] == sha1($_COOKIE['data'] . SECRETKEY)) {
		echo "Validated!\n";
	} else {
		echo "<blink>Not validated</blink>";
	}
} else {
	$_COOKIE['data'] = '00110100011';
	$_COOKIE['stamp'] = sha1($_COOKIE['data'] . SECRETKEY);
}
?>]]></example>

	<break/>
	<list fontsize="4em">
		<bullet>Easy validation of cookie data</bullet>
		<bullet>But not the 'best' way</bullet>
	</list>
</slide>
