From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.emacs.gnus.general/45372 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 12:05:59 -0400 Organization: The Happy Fun Ball Brigade Sender: owner-ding@hpc.uh.edu Message-ID: <02Jun24.115740edt.119250@gateway.intersystems.com> References: NNTP-Posting-Host: localhost.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: main.gmane.org 1024934925 17079 127.0.0.1 (24 Jun 2002 16:08:45 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Mon, 24 Jun 2002 16:08:45 +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 17MWOS-0004RD-00 for ; Mon, 24 Jun 2002 18:08:44 +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 17MWMd-0005tZ-00; Mon, 24 Jun 2002 11:06:51 -0500 Original-Received: by sina.hpc.uh.edu (TLB v0.09a (1.20 tibbs 1996/10/09 22:03:07)); Mon, 24 Jun 2002 11:07:10 -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 LAA21022 for ; Mon, 24 Jun 2002 11:06:58 -0500 (CDT) Original-Received: (qmail 6733 invoked by alias); 24 Jun 2002 16:06:34 -0000 Original-Received: (qmail 6728 invoked from network); 24 Jun 2002 16:06:33 -0000 Original-Received: from gateway.intersys.com (HELO intersystems.com) (198.133.74.253) by gnus.org with SMTP; 24 Jun 2002 16:06:33 -0000 Original-Received: by gateway.intersystems.com id <119250>; Mon, 24 Jun 2002 11:57:40 -0400 Original-To: "(ding)" X-Attribution: Rat In-Reply-To: (Simon Josefsson's message of "Mon, 24 Jun 2002 14:06:54 +0200 (CEST)") Original-Lines: 27 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:45372 X-Report-Spam: http://spam.gmane.org/gmane.emacs.gnus.general:45372 * Simon Josefsson on Mon, 24 Jun 2002 | That's probably impractical for most people, even a ~30 bit collision can | take about 10 minutes to find on a PC. Well, yes. That is the point of the hashcash system: to make delivery more expensive in CPU cycles than spammers are willing to pay. [...] | This is not how X-Hashcash works. The sender must generate a X-Hashcash | specific for each recipient. The recipient keeps a database of received | coins to prevent double spendings. There are some descriptions and links | at http://www.cypherspace.org/~adam/hashcash/. So, the recipient must keep a list of -all- hashes he has received? And must search that ever-increasing database for every message he receives? This puts more work on the recipient than on the sender. And what happens when a legitimate sender accidentally generates a hash that has been used already? The more I learn about X-Hashcash, the more I see that it is doomed to fail. -- Rat \ Ingredients of Happy Fun Ball include an Minion of Nathan - Nathan says Hi! \ unknown glowing substance which fell to PGP Key: at a key server near you! \ Earth, presumably from outer space. That and five bucks will get you a small coffee at Starbucks.