Briefs

New York Times (Dec 10, 2002) writes that As chief scientist of the Internet portal Yahoo, Dr. Udi Manber had a profound problem: how to differentiate human intelligence from that of a machine.

His concern was more than academic. Rogue computer programs masquerading as teenagers were infiltrating Yahoo chat rooms, collecting personal information or posting links to Web sites promoting company products. Spam companies were creating havoc by writing programs that swiftly registered for hundreds of free Yahoo e-mail accounts then used them for bulk mailings.

"What we needed," said Dr. Manber, "was a simple way of telling a human user from a computer program."

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Here is the full story from New York Times (free, but registration required).