January 28, 2004

Reverse Turing Tests

Alan Turing proposed the Turing test, which proposed the challenge of a human being distinguishing between a person and a computer. Lately, many e-commerce sites have implemented a technology that has been dubbed a Reverse Turing Test (RTT), which requires a human to prove that they can perform some task that computers are not good at. This technology is being deployed to prevent automated scripts from performing tasks such as registering for free email or opening account on ebay or paypal.

In the latest twist on this technology (found on slashdot), it appears that pronography sites have set up a man in the middle attack on whereby other people solve the RTT for the automated scripts in extrange for free porn. This is a case of computers using humans as oracles to answer challenges. If this catches on, it is not clear that RTTs will be effective in the long run. Posted by Avi Rubin at January 28, 2004 09:52 AM