From: tcmay@netcom.com (Timothy C. May)
Date: Wed, 3 Mar 93 11:52:34 PST
To: cypherpunks@toad.com
Subject: REPS: Filters Against Unwanted Messages
Message-ID: <9303031950.AA18115@netcom.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain


Attached below is a message wherein the author advertises in his .sig this item:

"(anon. postings not read)"

Simple, but it gets the point across. Expect to see more such declarations. 

In my off-line newsreader, Eudora, (which ironically is also the subject of
the message attached below--must be a plot), it's easy enough to mark all
the stuff from some anonymous site for deletion.

Such "filters" are a basic kind of positive reputation system and are in
use in many places. Some on this list have asked for this kind of filtering
to be incorporated (somehow) into NetNews readers. Maybe this will come
someday, but for now the best approach is to simply not read anonymous
postings, if that's important to you.

I want to also describe an important use of filters:

Publishers almost never accept unsolicited material. Manuscripts "thrown
over the transom," as the saying goes, are returned _unopened_ or sometimes
just thrown away. And the publishers are careful to publicize this fact.
Why?

Mainly to head off charges that they or one of their writers "stole" an
idea. Merely by opening the manuscript's envelope, they are exposing
themselves, potentially, to lawsuits from would-be authors who claim to see
elements of their ideas in someone else's "Movie of the Week" or Great
American Novel. So publishers and editors scrupulously refuse to look at
unsolicited manuscripts.

(I have heard, anecdotally, that the onset of electronic submissions is
causing them great distress. Without the option of "returned unopened,"
what are they to do? Various cryptographic solutions suggest
themselves...this could be a small niche market for some cypherentrepreneur
to fill, and could also be a way to get some P-K and reputation-filtering
software out in the world.)

Some forms of crypto-extortion can be handled the same way. (I described
this approach to Dean Tribble a while back.) Simply advertise widely--like
in your .sig--that you do not read messages unless they come from known
sources. 

Would-be extortionists ("Deposit 10 kilocrypts in this account or I will do
X") come to realize that they cannot easily contact their victim. To be
sure, other channels exist (anonymous postal mail, phone calls, routing
through other sources, etc.), but the lack of a direct channel makes the
initial threat harder to issue. It's a kind of crypto speed bump.

This approach, "I don't listen to extortion threats," is akin to "We don't
negotiate with hostage takers." Far from perfect, but still a "damping"
force.

-Tim

Here's the posting I cited earlier:

>Newsgroups: netcom.general
>Path: netcom.com!pfeiffer
>From: pfeiffer@netcom.com (Kevin Pfeiffer)
>Subject: Re: EUDORA for DOS?
>Message-ID: <1993Mar3.171249.26738@netcom.com>
>Organization: Pfeiffer Design Assoc.
>X-Newsreader: TIN [version 1.1 PL8]
>References: <1993Mar3.062411.9712@netcom.com>
>Date: Wed, 3 Mar 1993 17:12:49 GMT
>
>        You might look into pceudora... Can't speak for it, but Eudora (Mac)
>seems well-designed. No matter what seems to break my connections (me, the
>phone company, etc.) Eudora (and unix) leaves my mail intact at Netcom.
>Knock on wood.
>-- 
>   * Kevin Pfeiffer   <pfeiffer@netcom.com>   (anon. postings not read) *
>--