From owner-freebsd-current Fri Sep 1 17:13:45 2000 Delivered-To: freebsd-current@freebsd.org Received: from mailman.cs.ucla.edu (Mailman.CS.UCLA.EDU [131.179.128.30]) by hub.freebsd.org (Postfix) with ESMTP id 1779B37B422 for ; Fri, 1 Sep 2000 17:13:44 -0700 (PDT) Received: from rdwarrior.cs.ucla.edu (rdwarrior.cs.ucla.edu [131.179.192.88]) by mailman.cs.ucla.edu (8.9.1/UCLACS-5.0) with ESMTP id RAA10917; Fri, 1 Sep 2000 17:13:15 -0700 (PDT) Message-Id: <4.3.2.7.0.20000901171131.00ac5b80@panther.cs.ucla.edu> X-Sender: scottm@panther.cs.ucla.edu (Unverified) X-Mailer: QUALCOMM Windows Eudora Version 4.3.2 Date: Fri, 01 Sep 2000 17:13:35 -0700 To: adam@cypherspace.org From: Scott Michel Subject: Re: MACs vs Hash fns. and collision resistance Cc: freebsd-current@freebsd.org In-Reply-To: <200008260147.VAA22230@r00t.besiex.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG You could just as easily use a CRC function, which has the nice property of having a collision rate of 2^l, where l is the length of the CRC. CRCs are also pretty low-cost to compute relative to other methods. -scooter At 09:47 PM 8/25/00 -0400, you wrote: >[I see my post made it] > >To expand briefly on my comment about collision resistance > > > - the hash function constructed from using Blowfish in CBC mode you -- > > have to be careful how you use block ciphers to construct hash > > functions -- they have quite different properties. For example > > collision resistance is not generally important for a block cipher, > > but is all-important for a hash function To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message