Actually, (and oddly), GD::SecurityImage also has support for an Image::Magick backend as well. You're probably better off using the GD backend. The amount of support for fiddling with the image'd text is pretty low though, and probably fairly easy to crack. The included font with the package is pretty well suited for this application, though.

I personally have used this module for CAPTCHA work on my web app and also have had requests for an audio-version of the CAPTCHA image. I've been looking at the Authen::PluggableCaptcha module, but there's no audio support for it, yet. Sigh.

Hi, I' m the author of GD::SecurityImage. Image::Magick was an early addition and it was a request from someone else. It does not use the full power of Image::Magick (which is far more powerful than GD, but slower) and is merely a compatibility layer. You can use several different fonts and randomly changing styles/particles/scramble to make it hard for OCRs. But it may be possible to crack.. I don't know (I got zero feedback on this subject).

I didn't like Authen::Captcha' s approach with "graphic letters" and it's lack of plug-ability. It has it's own flat file database, while I prefer DB & sessions. I also like Tim Toady ;) I've added a sample part to show the generated images: GD::SecurityImage