By Paul Festa
Staff Writer, CNET News.com
AT&T defended its patenting of a technology to thwart antispam filters.,AT&T on Nov. 4 got the patent, described as "system and method for counteracting message filtering." The patent details a way to trick filters that compare digital messages to known pieces of spam, altering each message so that no two are exactly the same. It on ly foils countermeasure that use duplicate detection schemes.
AT&T Labs, the Florham Park, N.J., unit where the patented technology originated, said the patent was purely defensive.
"This is an arms race, and (Bell Labs researcher Robert Hall) tried to stay one step ahead of the spammers," said Michael Dickman, a spokesman for AT&T Labs. "He anticipated that spammers would try to change the message to circumvent the filters." AT&T said it has not yet decided how to use it.