From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.emacs.gnus.general/45378 Path: main.gmane.org!not-for-mail From: Stainless Steel Rat Newsgroups: gmane.emacs.gnus.general Subject: Re: [ANNOUNCE] contrib/hashcash.el spam fighter Date: Mon, 24 Jun 2002 15:26:57 -0400 Organization: The Happy Fun Ball Brigade Sender: owner-ding@hpc.uh.edu Message-ID: <02Jun24.151839edt.119751@gateway.intersystems.com> References: <02Jun24.115740edt.119250@gateway.intersystems.com> NNTP-Posting-Host: localhost.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: main.gmane.org 1024946918 12665 127.0.0.1 (24 Jun 2002 19:28:38 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Mon, 24 Jun 2002 19:28:38 +0000 (UTC) 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 17MZVt-0003I9-00 for ; Mon, 24 Jun 2002 21:28:38 +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 17MZVH-0006v6-00; Mon, 24 Jun 2002 14:27:59 -0500 Original-Received: by sina.hpc.uh.edu (TLB v0.09a (1.20 tibbs 1996/10/09 22:03:07)); Mon, 24 Jun 2002 14:28:19 -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 OAA21424 for ; Mon, 24 Jun 2002 14:28:07 -0500 (CDT) Original-Received: (qmail 11543 invoked by alias); 24 Jun 2002 19:27:43 -0000 Original-Received: (qmail 11536 invoked from network); 24 Jun 2002 19:27:40 -0000 Original-Received: from gateway.intersys.com (HELO intersystems.com) (198.133.74.253) by gnus.org with SMTP; 24 Jun 2002 19:27:40 -0000 Original-Received: by gateway.intersystems.com id <119751>; Mon, 24 Jun 2002 15:18:39 -0400 Original-To: "(ding)" X-Attribution: Rat In-Reply-To: (Simon Josefsson's message of "Mon, 24 Jun 2002 18:41:48 +0200") Original-Lines: 33 User-Agent: Gnus/5.090006 (Oort Gnus v0.06) XEmacs/21.1 (Cuyahoga Valley, i686-pc-linux) Precedence: list X-Majordomo: 1.94.jlt7 Xref: main.gmane.org gmane.emacs.gnus.general:45378 X-Report-Spam: http://spam.gmane.org/gmane.emacs.gnus.general:45378 * Simon Josefsson on Mon, 24 Jun 2002 | No, it does not work like that. Each coin has a limited life length | (e.g., 28 days), the receiver only has to keep track of valid ones | within the time window. I-the-spammer generate a new hash every hundred thousand messages or so. I-the-spammer easilly circumvent the X-Hashcash system, and without even trying hard. | This is explained on the web page... I looked. The X-Hashcash scheme is fundamentally flawed. It relies on the sender being honest when he says that he spent the time generating the hash when he puts it in his headers. It does not stop spam. It only gives the end user a useless header and an fHuge database of signatures. [...] | > The more I learn about X-Hashcash, the more I see that it is doomed to | > fail. | Do you have a better idea? Hashcash at the MTA level. That is enforceable because the recipient says "find X bits of collision with this hash or your message will not be accepted". It does not rely on the good faith of the sender, it forces the sender to solve a problem in real time. Or make spam a federal crime like junk faxes and then enforce it. -- Rat \ Caution: Happy Fun Ball may suddenly Minion of Nathan - Nathan says Hi! \ accelerate to dangerous speeds. PGP Key: at a key server near you! \ That and five bucks will get you a small coffee at Starbucks.