CAPTCHA is a simple test to determine if a user is a computer or a human. It is used to prevent spam abuse on the websites. The goal of this tutorial is to demonstrate how to make your own simple CAPTCHA protection using PHP and AJAX technologies.
If you are developing a password-protected web site, you have to make a decision about how to store user password information securely. This article will show you how to encrypt user passwords with the md5 algorithm and how to start using encrypted passwords if you already have a user database ready.
MySQL injection in PHP-based websites is a serious security problem. This article will tell you how to know if your site is vulnerable to this issue and correct this problem.