The future of CAPTCHAs can be ill-fated

According to an article in Forbes, the future of CAPTCHAs can be ill-fated.

Because every day spam software writers develop their spam bots to evade the protection provided by randomly distorted text images.

Luis von Ahn says that reCAPTCHA's audio version is unbreakable for now, but with a cost: the humans too can't solve the puzzle 30% of the time.

So we should start looking at other alternatives for recognizing humans apart from the computers. A company called Pramana works on a way of recognizing humans by observing their mouse movements and other behaviour while browsing the web page.

But I think this alternative is much more vulnerable compared to the current CAPTCHA technologies. This is because the attacker can too observe the behaviour pattern of a sufficient number of users and then build derivations originating from them.