Building a Better CAPTCHA Mousetrap

CAPTCHA, a system used for blocking spam bots from posting to blogs and web sites, has come under fire in the past year. Systems used by Yahoo, Hotmail and Gmail were cracked last year, making it less attractive to use on e-mail and web sites.

But, in this interesting article in Computer World, CAPTCHA seems to be making somewhat of a come back with some innovative new approaches. Rather than just capture scrambled letters, new systems use word matching and images.

The article traces the history of capture through its cracking to present day developments, including reCAPTCHA, SQ-PIX and ALIPR, among others.

CAPTCHA stands for Completely Automated Public Turing Test to Tell Computers and Humans Apart.