Today I came across a new type of captcha: animated gifs. The animation makes it more difficult to read the characters, however this is just another level of spam-prevention. The next level could be flash-video streams.
Rant about today’s solutions
I hate captchas – I really do. On the one hand they only hinder Spammers, but they don’t block them totally. It is simply a war of steadily evolving technologies against each other. And the side which looses in the end are average humans because at some point the captcha will be to difficult to read for humans while the spam bots will still be able to read them. Btw., on average I need two attempts already to get a captcha right.
On the other hand this technology is something I never really got. Why use captchas? Why not use standard spam prevention software? It should be pretty easy to change spamassassin to work together with WordPress. Or Dspam or one of the other available spam filters. I mean the rules should be pretty easy: if it includes an URL it gets some minus points, if it has more than one URL and even clusters them it gets even more minus points. Akismet uses such filters and these filters are pretty good. Also, such a way of filtering comments would make it possible again for blind people to post comments to blogs.
Tomorrow’s solution (which will be crap as well)
Anyway, enough rant about current captchas, forward to the future. I’d like to predict that we will see pretty soon the first video-stream captchas. These flash-embedded video will make it even harder for bots to read the captchas but are still quite easy to generate and read for humans. The trick would be to have an animation which would show floating objects which would transform in to other objects all the time. At a random time the new objects would be readable characters for a short moment. This stream could be like 10 seconds and would be repeated all the time. The important parts are the fact that you cannot predict when it will exactly show the characters and that also there are information all the time. If you want to use a spam bot against such a stream you have to analyze its entire data stream which would result in quite some CPU load – and that would make it yet again a bit harder for the spam bots. Not impossible though, but maybe hard enough.
Still, this solution is not usable from a blind person’s point of view, and again the simple spam filter tool looks more effective to me.