Re: Anti-Spambot: what algorithm should be used?

[dlv@bwalk.dm.com (Dr.Dimitri Vulis KOTM)]

owner-cypherpunks@manifold.algebra.com writes:

> As we all know, there exist certain programs, called "spambots", whose
> task is to post various messages to many newsgroups simultaneously.
> 
> Besides their posting functionality, certain spambot programs take
> special care to make their spams undetectable by anti-spambots. In
> particular, they can be programmed to modify certain fields or the
> message text itself in such a way that these messages would not look
> unique, but would still carry the same content.

I just came up with yet another brilliant idea how to combine Usenet
marketing with e-cash. Suppose Alice runs an advertizing agency and gets
paid to publicize certain messages of commercial or political nature.

She sets up a Web page listing the catalog of regexps that she wishes to
publicize. Something like:

1. Visit.*teens.*http://www.xxxfoo.bar
2. Elect.*John M. Grubor.*sheriff
4. For a drooling good time.*900-555-5555
3. Drink Kaka Cola

and a price list for each regexp - say, $2 for posting this regexp in a
moderated newsgroup, 50c for the Big 8, 25c for alt and regionals. I'm
not sure if cross-posts should be discounted. Assuming there are several
such Alices, the prices will be set by supply and demand.

Suppose Bob, in search of a few quick bucks, comes across Alice's site.
We'd have to think of a protocol, but Alice assigns Bob an id which he
must mention together with the regexps in order to get credit. Alice and
Bob enter a contract. Bob puts one or more of Alice's regexps in his
Usenet articles - most likely in the .signature. For example:

   From: bob
   Newsgroups: rec.sports.phishing,alt.fan.alice
   Message-ID: <123@bob.server>
   <something phishing-related>
   --
   Elect John M. Grubor sheriff!!!            Alice's ID# 123456
   I am Bob! I am Bob! I am Bob the Poster!   Drink Kaka Kola

Alice's bot searches the Usenet feed (like K*bo and S*rd*r) for the
regexps that she is paid to promote. When she encounters Bob's article,
it extracts Bob's ID and the Message-Id, counts the distinct regexps, and
the newsgroups, and credits Bob's account.

If Carol follows up on Bob's article and quotes Bob's regexps and ID#,
then Bob gets paid again. If somehow an article contains the ID# of two
or more of Alice's agents, they split the fee.

Alice's contract can also specify that if a third party forges a cancel
within a week for Bob's Usenet article containing the regexp, then Alice
will pay nothing and let Bob sue the forger for the lost income. (This
may become moot as more and more ISPs ignore forged cancels.) This gives
Bob the insentive to spam intelligently - not to trigger any cancelbots
and not to have his plug pulled by his ISP.

Alice can also put some reasonable caps on the number of repetitions
because if Bob posts the same regexp 10,000 times, the marginal exposure
is less from Bob than from a newbie Carol. Again, if there are several
such Alices, the market will take care of negotiating such details.

Actually, this doesn't even need e-cash - Alice can pay regular $$$.
Hi Ross - if you're still on these lists, I think you'll like this.

---

<a href="mailto:dlv@bwalk.dm.com">Dr.Dimitri Vulis KOTM</a>
Brighton Beach Boardwalk BBS, Forest Hills, N.Y.: +1-718-261-2013, 14.4Kbps