DCC is patented

John R Levine johnl@iecc.com
Wed Oct 27 17:09:32 UTC 2004

I recently learned about patent 6,330,590.  It was filed in Jan 1999,
which means the work it covers was done in 1998, and fairly broadly covers
spam filtering by counting message signatures.

A PDF copy of the patent is http://www.taugh.com/6330590.pdf

If you haven't read patents before, the first part describes the invention
but isn't legally very important.  The crucial bits are the claims which
start on page 6.  Claims 1 and 2 and claim 30 look a lot like DCC.

Anti-spam vendor Commtouch recently bought the patent:

They say they're going to start selling licenses.  Uh, oh. How long ago
did you start work on DCC?  If it's older than Jan 1998, you're OK.  If
not, this guy probably got there first.

John Levine, johnl@iecc.com, Primary Perpetrator of "The Internet for Dummies",
Information Superhighwayman wanna-be, http://iecc.com/johnl, Mayor
"I dropped the toothpaste", said Tom, crestfallenly.

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