<?php require_once 'tutorial_autoload.php'; // generate a token and save it in the session or in a file/database $pattern = "1234567890abcdefghijklmnopqrstuvwxyz"; $token = ""; for( $i = 1; $i <= 6 ; $i++ ) { $token .= $pattern{rand( 0, 36 )}; } $encryptedToken = sha1( $token ); // save the $encryptedToken in the session session_start(); $_SESSION['encryptedToken'] = $encryptedToken; // also generate a distorted image which contains the symbols from $token and use it ?>