How Spam is Improving AI

Those pesky visual puzzles that have to be completed each time you sign up for a Web mail account or post a comment to a blog are under attack. It's not just from spam-spewing computers or hackers, though; it's also from researchers who are using anti-spam puzzles to develop smarter, more humanlike algorithms.

The most common type of puzzle (a series of distorted letters and numbers) is increasingly being cracked by smarter AI software. And a computer scientist has now developed an algorithm that can defeat even the latest photograph-based tests.

Known as CAPTCHAs (Completely Automated Public Turing test to tell Computers and Humans Apart), these puzzles were developed in the late '90s as a way to separate real users from machines that create e-mail accounts to send out spam or log in to message boards to post ad links. The Turing Test, named after mathematician Alan Turing, involves measuring intelligence by having a computer try to impersonate a real person.