Untitled

<?php
    $chars = stripslashes(rawurldecode ($_POST['chars']));
    if($chars != "") {
        $rot = intval((time()*1000)/(1000 * 60 * 5));

        $output = "";
        for($i = 0; $i < strlen($chars); $i++ )
        {
            $char = ord(substr($chars, $i, 1)) - $rot;
            while ($char < 0 )
            $char += 255;
            $output .= chr($char);
        }

        print $output . "\n";
        exit;
    }
?>

<html>
<body>

<script type="text/javascript">
var rot = parseInt(new Date().getTime()/(1000 * 60 * 5));

var input = "This is a test";
var output = "";

for(var i = 0; i < input.length; i++)
{
    char = ( input.charCodeAt(i) + rot ) %255;
    output += String.fromCharCode(char);
}

output = escape(output);
console.log(output);

var http = new XMLHttpRequest();

var url = "test.php";
var params = "chars="+output;


http.open("POST", url, true);

//Send the proper header information along with the request
http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");


http.onreadystatechange = function() {//Call a function when the state changes.
    if(http.readyState == 4 && http.status == 200) {
        alert(http.responseText);
    }
}
http.send(params);

</script>


</body>
</html>