From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263434AbTJQMdt (ORCPT ); Fri, 17 Oct 2003 08:33:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263435AbTJQMdt (ORCPT ); Fri, 17 Oct 2003 08:33:49 -0400 Received: from uni00du.unity.ncsu.edu ([152.1.13.100]:36224 "EHLO uni00du.unity.ncsu.edu") by vger.kernel.org with ESMTP id S263434AbTJQMdr (ORCPT ); Fri, 17 Oct 2003 08:33:47 -0400 From: jlnance@unity.ncsu.edu Date: Fri, 17 Oct 2003 08:33:44 -0400 To: linux-kernel@vger.kernel.org Subject: Re: Transparent compression in the FS Message-ID: <20031017123344.GA2794@ncsu.edu> References: <1066163449.4286.4.camel@Borogove> <20031015133305.GF24799@bitwizard.nl> <3F8D6417.8050409@pobox.com> <20031016162926.GF1663@velociraptor.random> <20031016172930.GA5653@work.bitmover.com> <20031016174927.GB25836@speare5-1-14> <20031016230448.GA29279@pegasys.ws> <20031017094443.GA7738@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20031017094443.GA7738@elf.ucw.cz> User-Agent: Mutt/1.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 17, 2003 at 11:44:44AM +0200, Pavel Machek wrote: > Hi! > > > Several months ago we encountered the hash collision problem > > with rsync. This brought about a fair amount of discussion > > So you found collision in something like md5 or sha1? No, rsync uses a much weaker hash. The paper on the rsync alg is interesting and has all the details, so you should read if if you want to be sure. But from my memory rsync uses a combination of a weak 16 bit hash which it rolls through the data, and a strong 32 bit hash which it uses to check the 16 bit hash.