3DCaptcha

About

3DCaptcha is the "captcha nice to humans, bad to machines". It is written in PHP and features:

A new approach to captchas, using human's spatial cognition abilities to differentiate humans from machines.
It uses a markov-chain to generate words that resemble human language and are easy to type, yet avoid dictionary lookups.
It filters profane language.
It's easy to deploy.

Enjoy!

3DCaptcha

You can get the latest release here:

You can get the latest source code here:

With this command you can anonymously check out the latest project source code:

    svn checkout http://3dcaptcha.googlecode.com/svn/trunk/ 3dcaptcha

3DCaptcha requires PHP4, with gd image support. To find out how to install gd check out this URL:

You'll also need to add TrueType support.

By default, 3DCaptcha uses PHP's $_SESSION variable. If you have a custom session handler, simply replace the references to the $_SESSION variable.

To generate a word, include TextGen.php. This generates a text. To display an image, add this HTML tag:

    <img src="3DCaptcha.php" alt="captcha">

The php code will generate an image with the text in the $_SESSION variable.