From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.emacs.gnus.general/45359 Path: main.gmane.org!not-for-mail From: Simon Josefsson Newsgroups: gmane.emacs.gnus.general Subject: Re: [ANNOUNCE] contrib/hashcash.el spam fighter Date: Sun, 23 Jun 2002 19:59:30 +0200 Sender: owner-ding@hpc.uh.edu Message-ID: References: NNTP-Posting-Host: localhost.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: main.gmane.org 1024855206 27732 127.0.0.1 (23 Jun 2002 18:00:06 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Sun, 23 Jun 2002 18:00:06 +0000 (UTC) Cc: "(ding)" Return-path: Original-Received: from malifon.math.uh.edu ([129.7.128.13]) by main.gmane.org with esmtp (Exim 3.33 #1 (Debian)) id 17MBef-0007DB-00 for ; Sun, 23 Jun 2002 20:00:05 +0200 Original-Received: from sina.hpc.uh.edu ([129.7.128.10] ident=lists) by malifon.math.uh.edu with esmtp (Exim 3.20 #1) id 17MBeP-0002PX-00; Sun, 23 Jun 2002 12:59:49 -0500 Original-Received: by sina.hpc.uh.edu (TLB v0.09a (1.20 tibbs 1996/10/09 22:03:07)); Sun, 23 Jun 2002 13:00:10 -0500 (CDT) Original-Received: from sclp3.sclp.com (qmailr@sclp3.sclp.com [209.196.61.66]) by sina.hpc.uh.edu (8.9.3/8.9.3) with SMTP id MAA18820 for ; Sun, 23 Jun 2002 12:59:57 -0500 (CDT) Original-Received: (qmail 18018 invoked by alias); 23 Jun 2002 17:59:31 -0000 Original-Received: (qmail 18013 invoked from network); 23 Jun 2002 17:59:31 -0000 Original-Received: from 178.230.13.217.in-addr.dgcsystems.net (HELO yxa.extundo.com) (217.13.230.178) by gnus.org with SMTP; 23 Jun 2002 17:59:31 -0000 Original-Received: from latte (yxa.extundo.com [217.13.230.178]) (authenticated bits=0) by yxa.extundo.com (8.12.4/8.12.4) with ESMTP id g5NHxTlf022383; Sun, 23 Jun 2002 19:59:29 +0200 Original-To: Stainless Steel Rat Mail-Copies-To: nobody X-Hashcash: 020623:ratinox@peorth.gweep.net:ed03924298d3ee14 X-Hashcash: 020623:ding@gnus.org:84cba029b17e18d1 In-Reply-To: (Stainless Steel Rat's message of "Sun, 23 Jun 2002 11:20:25 -0400") Original-Lines: 18 User-Agent: Gnus/5.090007 (Oort Gnus v0.07) Emacs/21.3.50 (i686-pc-linux-gnu) Precedence: list X-Majordomo: 1.94.jlt7 Xref: main.gmane.org gmane.emacs.gnus.general:45359 X-Report-Spam: http://spam.gmane.org/gmane.emacs.gnus.general:45359 Stainless Steel Rat writes: > * Simon Josefsson on Sun, 23 Jun 2002 > | If you send mail to people that you know only accept mail with a > | X-Hashcash: of a certain bit size, > > If I send mail to people that only accept mail with a X-Hashcash of a > certain bit size, I can pick a hash out of a small table of pregenerated > hashes of that size or larger, circumventing the "security" of the scheme. Pregenerated or not, the computation of the field requires someone to burn CPU time, if the limit is set sufficiently high spammers will find it costs too much to send spam, which is the point. I'm not saying it is a perfect scheme. Spamming is a social problem and cannot be eliminated completely by technical means. But experimenting with different technical solutions could perhaps eventually improve the situation.