Web www.gerd-tentler.de
Version 1.3 (released Dez. 31, 2016) [Download]


This PHP script creates an image with a security code (known as "captcha") that can be used to protect e.g. your guestbook from spam. It requires PHP 4.1.0 or higher with session support and GD library. The created image with the security code looks like this:

Why create an image? The answer is simple: any text that appears on a web page (even in a hidden input field) can be copied. In order to copy a text from an image you need special software (OCR), and even then you cannot be sure that the software recognizes the characters correctly.

Please have a look at the sample page to see how a form with integrated security code looks like and works. It is also included in seccode.zip, so you can have a look at the source code there.