Antispam Circumvention Technology Patented By AT&T

by Glen Shapiro, LawAndTax-news.com, New York

20 November 2003

Telecommunications firm, AT&T has been granted a patent for technology designed to circumvent certain types of anti-spam filter, much to the puzzlement of industry observers.

Patent No. 6,643,686, applied for by Bell Labs researcher, Robert Hall in December 1999, and granted on November 4, covers technology counteracting message filtering.

According to the filing, this describes: "A system and method for circumventing schemes that use duplication detection to detect and block unsolicited e-mail (spam.) An address on a list is assigned to one of m sublists, where m is an integer that is greater than one. A set of m different messages are created. A different message from the set of m different messages is sent to the addresses on each sublist. In this way, spam countermeasures based upon duplicate detection schemes are foiled."

This means that a spam filter which compares e-mails with known spam could be effectively fooled, as no two messages would be the same.

The move has baffled many within the industry, who cannot understand why AT&T would need to own the rights to such technology.

However, speaking to Cnet News, AT&T spokesman, Michael Dickman explained that:

"This is an arms race and (Robert Hall) tried to stay one step ahead of the spammers. He anticipated that spammers would try to change the message to circumvent the filters."

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