A group of boffins from Carnegie Mellon University is proposing that inkblot-style patterns form the basis of a system to replace CAPTHCAs, and is offering an open challenge to see how well it works.

While the CAPTCHA has been successful in preventing some forms of attack, such as comment-spam on Web forums, CAPTCHA-protected pages and passwords still come under attacks of various kinds, all the way down to paying people cents-per-hour to attack them.

The Carnegie Mellon proposal is for randomly-generated inkblots be presented instead of CAPTCHAs. Dubbed “GOTCHAs” (Generating panOptic Turing Tests to Tell Computers and Humans Apart) by the researchers, the aim is to defeat dictionary attacks, since the password cracker needs human feedback, even if it has access to the bits that generated the puzzle.

SOURCE: theregister.co.uk