From owner-freebsd-security@FreeBSD.ORG Thu Aug 19 14:49:05 2004 Return-Path: Delivered-To: freebsd-security@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DEDAC16A4CE for ; Thu, 19 Aug 2004 14:49:05 +0000 (GMT) Received: from lvlworld.com (dsl-38.226.240.220.dsl.comindico.com.au [220.240.226.38]) by mx1.FreeBSD.org (Postfix) with SMTP id 6709F43D53 for ; Thu, 19 Aug 2004 14:48:46 +0000 (GMT) (envelope-from tigger@onemoremonkey.com) Received: (qmail 2603 invoked from network); 19 Aug 2004 14:50:33 -0000 Received: from unknown (HELO piglet.goo) (192.168.1.120) by eeeor.goo with SMTP; 19 Aug 2004 14:50:33 -0000 Date: Fri, 20 Aug 2004 00:48:43 +1000 From: Tig To: freebsd-security@freebsd.org Message-Id: <20040820004843.011b8de8@piglet.goo> In-Reply-To: <20040818182957.GK346@cowbert.net> References: <200408181724.i7IHORYl013375@bunrab.catwhisker.org> <20040818175804.GI346@cowbert.net> <41239B0C.1000703@rdslink.ro> <20040818182957.GK346@cowbert.net> X-Mailer: Sylpheed-Claws 0.9.12 (GTK+ 1.2.10; i386-portbld-freebsd5.2.1) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Bogosity: No, tests=bogofilter, spamicity=0.896238, version=0.17.5 Subject: Re: Report of collision-generation with MD5 X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Security issues [members-only posting] List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 19 Aug 2004 14:49:06 -0000 On Wed, 18 Aug 2004 14:29:57 -0400 "Peter C. Lai" wrote: > On Wed, Aug 18, 2004 at 09:08:12PM +0300, Claudiu wrote: > > hello, > > > > please explain what do you mean by "reverse the hash". Is this the > > recreation of the originial message from its hash ? > > The short answer is yes. The slightly longer answer is that such is > only one specific case. The general case is that the digest should not > reveal any information about the original message. > If this is the case, then it would be very cool! Imagine sending 32 bytes, then 'reverse the hash' to get XX MB's worth of data :] That would be great compression! -Tig