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Touch Typists Could Help Stop Spammers in Their Tracks

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Newcastle University computer scientists have developed Magic Bullet, a computer game that turns a tedious manual labeling task into entertainment, giving companies a better chance of tracking online spammers.

To test the robustness of CAPTCHAs (Completely Automated Public Turing Test to Tell Computers and Humans Apart), which are widely used to prevent spammers from creating email accounts they can use to spread junk email, involves acquiring a set of labeled samples. However, it is difficult for computers to create the labels, so the task usually is completed by human researchers, which can be tedious and expensive. "For the first time, this simple game turns it into a fun experience with a serious application as it also achieves a labeling accuracy of as high as 98 percent," says Jeff Yan, leader of the effort.

Magic Bullet players face each other in teams of two in an online shooting game. Teams and players cannot communicate with each other, and security techniques are used to ensure the players are geographically separated to reduce the chances of cheating. In each round, a randomly chosen segmented CAPTCHA character appears and will move toward the target only when both players correctly identify it before their opponents. The answers given by the winning team can serve as accurate labels for the segments. Yan says the average game session creates 25 correct labels per minute, which could be improved upon if touch typists played the game.

From Newcastle University
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