Subject: [Asrg] Not again - another challenge/response patent

From: [email-masked]
Date: Mon, 24 Mar 2003 13:00:17 -0800

This is ridiculous. Yet another bloody challenge-response patent. :(

  http://about.mailblocks.com/press_0324_2003.html

  ...  The Mailblocks service, available today, uses its patented technology
  to eliminate spam ...

It's a simple challenge-response system.  Nothing exciting or innovative
involved, as far as I can see.  I can't find any patents in the uspto
database though.  FYI,

--j.
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From: Brad Templeton <[email-masked]>
Date: Mon, 24 Mar 2003 14:08:23 -0800

Here is the patent reference.

  Method and system for filtering electronic messages

Abstract

The present invention provides a system and method for filtering 
unsolicited electronic commercial messages. A system and method 
according to the present invention for screening out unsolicited 
commercial messages comprises the steps of receiving a message from a 
sender, sending a challenge back to the sender, receiving a response to 
the challenge, and determining if the response is a proper response.

Inventors:  Cobb; Christopher Alan (500 Beale St. Apt.120, San 
Francisco, CA 94105) Appl. No.:   921950  Filed:  August 26, 1997

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=/netahtml/search-adv.htm&r=4&f=G&l=50&d=PTXT&p=1&p=1&S1=6,199,102&OS=+6,199,102&RS=6,199,102

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From: "David Anderson" <[email-masked]>
Date: Mon, 24 Mar 2003 18:15:28 -0600

Yes, it is ridicules.  Why not patent the english language as conversations
are like hand shakes?

 Fortunately, to beat a patent you just need to be different and publish it
in the open before it is re-patented.

 I am no patent lawyer, but once an effective solution gets out in the wild
with source, the jeanie will never be back in the bottle.

 Handshaking via mail I think has promise but with twists to what I have
seen so far.  Compute a question into a graphic and send it off.  The
graphic could ask simple questions like spell or type in the word "the" and
reply.  Reads would have to recognize such graphics and display them.
Fonts, colors and thread lines like what is in currency can be added as so
to foul up checksums for easy guessing and OCR technologies.

 Once confirmed, a serial number can be stored by the confirming mailer and
server to avoid future prompts, say a 4096 bit key.  Why such a large key?
Two parts, make it really hard to guess and to make bandwidth impossible for
the spammer.

 Several advantages exist here, one persons spam may be another persons joy.
By using a hash with the key and email address of the recipient both can be
satisfied.

 To subscribe to mail lists like these, sendmail relays need a web interface
for people to go to add in the senders mail address and if the MX matches
the sender, it is allowed through.  If not, just hold open the session....

 One thing all relays fighting spam need to do is make it rude for the
offending parties.  I have found firewall blocks, black holing their packets
drive them crazy enough to (eventually) remove your people from the list.

 And the solution needs to be in C/C++.  Today's computers are relatively
cheap but tossing a million messages a day has to take a few less bytes than
50M to process.

 It needs to be open source so it doesn't bog down in vendor greed.

 Now is anyone working on a open source project like this and need some help
in design and coding?

Dave