Kevin Larson, a researcher at Microsoft, has come up with a unique idea for combating e-mail spam – kittens!

Typically, would-be spammers use free e-mail services like Hotmail and Yahoo mail for sending their spam messages. These mail services attempt to prevent automated signups for new mailboxes by using a protocol referred to as HIPS – Human Interactive Proofs. You've seen them. A box appears containing slightly distorted letters or numbers and you are asked to type what you see. The HIPS were designed to prevent machines from accessing the site, or, in the case of mail services, signing up automatically for mail addresses from which spam messages can be launched.

Recently, the spamming community has begun finding out ways to have their machines recognize the HIPS characters, thus defeating the protection. Companies that use HIPS can make the characters harder to detect, but the spammers continue to rise to the occasion. Enter Mr. Larson.

Speaking at the annual TypeCon conference earlier this month in Seattle, Larson suggested that using photos in place of the HIPS letters and numbers – for example, photos of kittens – might possibly fool the spammers. The process would involve displaying a group of 16 or more photos and asking the user to identify which photos are of a certain type.

You can experiment with a beta service of the technology, called Asirra, on the Microsoft Research web site. Identify the kitten photos correctly and you are notified that you indeed are a human. If you like the images you see, you can click a link that takes you to a pet adoption web site.

"It's possible that kittens are the wave of the future," Larson commented at the convention, an annual event hosted by the Society of Typographic Aficionados.