IETF Logo Mail Archive

Re: [Asrg] 3. Proof-of-work analysis

"Alan DeKok" <aland@ox.org> Tue, 18 May 2004 16:00 UTC

Received: from optimus.ietf.org (optimus.ietf.org [132.151.1.19]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id MAA24580 for <asrg-archive@odin.ietf.org>; Tue, 18 May 2004 12:00:54 -0400 (EDT)
Received: from localhost.localdomain ([127.0.0.1] helo=www1.ietf.org) by optimus.ietf.org with esmtp (Exim 4.20) id 1BQ6zG-0003Su-SS for asrg-archive@odin.ietf.org; Tue, 18 May 2004 11:58:39 -0400
Received: (from exim@localhost) by www1.ietf.org (8.12.8/8.12.8/Submit) id i4IFwc5u013320 for asrg-archive@odin.ietf.org; Tue, 18 May 2004 11:58:38 -0400
Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by optimus.ietf.org with esmtp (Exim 4.20) id 1BQ6ur-0002GA-I9 for asrg-web-archive@optimus.ietf.org; Tue, 18 May 2004 11:54:05 -0400
Received: from ietf-mx (ietf-mx.ietf.org [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id LAA24190 for <asrg-web-archive@ietf.org>; Tue, 18 May 2004 11:54:03 -0400 (EDT)
Received: from ietf-mx.ietf.org ([132.151.6.1] helo=ietf-mx) by ietf-mx with esmtp (Exim 4.32) id 1BQ6uq-0003JP-EQ for asrg-web-archive@ietf.org; Tue, 18 May 2004 11:54:04 -0400
Received: from exim by ietf-mx with spam-scanned (Exim 4.12) id 1BQ6tp-0003Gp-00 for asrg-web-archive@ietf.org; Tue, 18 May 2004 11:53:02 -0400
Received: from optimus.ietf.org ([132.151.1.19]) by ietf-mx with esmtp (Exim 4.12) id 1BQ6t2-0003FG-00 for asrg-web-archive@ietf.org; Tue, 18 May 2004 11:52:12 -0400
Received: from localhost.localdomain ([127.0.0.1] helo=www1.ietf.org) by optimus.ietf.org with esmtp (Exim 4.20) id 1BQ6m5-0006ZY-HE; Tue, 18 May 2004 11:45:01 -0400
Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by optimus.ietf.org with esmtp (Exim 4.20) id 1BQ6eI-0003pM-BI for asrg@optimus.ietf.org; Tue, 18 May 2004 11:36:58 -0400
Received: from ietf-mx (ietf-mx.ietf.org [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id LAA23248 for <asrg@ietf.org>; Tue, 18 May 2004 11:36:56 -0400 (EDT)
Received: from ietf-mx.ietf.org ([132.151.6.1] helo=ietf-mx) by ietf-mx with esmtp (Exim 4.32) id 1BQ6eH-0002M1-AW for asrg@ietf.org; Tue, 18 May 2004 11:36:57 -0400
Received: from exim by ietf-mx with spam-scanned (Exim 4.12) id 1BQ6dP-0002JC-00 for asrg@ietf.org; Tue, 18 May 2004 11:36:03 -0400
Received: from newgiles.striker.ottawa.on.ca ([205.150.200.131] helo=mail.nitros9.org) by ietf-mx with esmtp (Exim 4.12) id 1BQ6cT-0002Fw-00 for asrg@ietf.org; Tue, 18 May 2004 11:35:05 -0400
Received: from newgiles.nitros9.org (localhost [127.0.0.1]) by mail.nitros9.org (Postfix) with ESMTP id 78E5B16FCA for <asrg@ietf.org>; Tue, 18 May 2004 11:40:39 -0400 (EDT)
From: Alan DeKok <aland@ox.org>
To: asrg@ietf.org
Subject: Re: [Asrg] 3. Proof-of-work analysis
In-Reply-To: Your message of "Tue, 18 May 2004 01:04:31 EDT." <200405180510.BAA26322@Sparkle.Rodents.Montreal.QC.CA>
Message-Id: <20040518154039.78E5B16FCA@mail.nitros9.org>
Sender: asrg-admin@ietf.org
Errors-To: asrg-admin@ietf.org
X-BeenThere: asrg@ietf.org
X-Mailman-Version: 2.0.12
Precedence: bulk
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/asrg>, <mailto:asrg-request@ietf.org?subject=unsubscribe>
List-Id: Anti-Spam Research Group - IRTF <asrg.ietf.org>
List-Post: <mailto:asrg@ietf.org>
List-Help: <mailto:asrg-request@ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/asrg>, <mailto:asrg-request@ietf.org?subject=subscribe>
List-Archive: <https://www1.ietf.org/mail-archive/working-groups/asrg/>
Date: Tue, 18 May 2004 11:40:39 -0400
X-Spam-Checker-Version: SpamAssassin 2.60 (1.212-2003-09-23-exp) on ietf-mx.ietf.org
X-Spam-Status: No, hits=0.0 required=5.0 tests=AWL autolearn=no version=2.60

der Mouse <mouse@Rodents.Montreal.QC.CA> wrote:
> > I'm just idly curious (like you I have zero confidence in
> > proof-of-work schemes) but why wouldn't they all be equivalent to
> > "don't send me your next command for (at least) N seconds or I'll
> > drop the connection"?
> 
> No, because "wait for N seconds" is parallelizable across many
> connections, whereas "do N cpu-seconds of work" isn't.

  Many MTA's can limit the number of simultaneous connections from
clients, and can group the connections into pools.  Until the spam
attempts went up by another order of magnitude, I was quite successful
in limiting my MTA to ~50 connections, with ~10 reserved for the pool
of MX's that most of my traffic came from.

  In the end, it was easier to discard the domain, and move to another
one.  But that solution doesn't scale, which is why we're here.

  Alan DeKok.

_______________________________________________
Asrg mailing list
Asrg@ietf.org
https://www1.ietf.org/mailman/listinfo/asrg

v2.23.0 | Report a Bug | By Email