KCAPTCHA project - CAPTCHA.ruKCAPTCHA is a free and open source PHP solution to generate human validation images (CAPTCHA). KCAPTCHA is meant to be a very strong protected one but requires no special hosting features, only PHP with GD library. Example (generates on fly, so refresh this page to see another variants): How it works: script creates session and writes to it with name $_SESSION['captcha_keystring'] randomly generat
Client Challenge
