From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262161AbUCEC0O (ORCPT ); Thu, 4 Mar 2004 21:26:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262163AbUCEC0O (ORCPT ); Thu, 4 Mar 2004 21:26:14 -0500 Received: from 104.engsoc.carleton.ca ([134.117.69.104]:63892 "EHLO quickman.certainkey.com") by vger.kernel.org with ESMTP id S262161AbUCEC0N (ORCPT ); Thu, 4 Mar 2004 21:26:13 -0500 Date: Thu, 4 Mar 2004 21:14:01 -0500 From: Jean-Luc Cooke To: dean gaudet Cc: Christophe Saout , Carl-Daniel Hailfinger , Linux Kernel Mailing List Subject: Re: dm-crypt, new IV and standards Message-ID: <20040305021401.GA13805@certainkey.com> References: <20040220172237.GA9918@certainkey.com> <20040221164821.GA14723@certainkey.com> <20040303150647.GC1586@certainkey.com> <20040304132430.GA8213@certainkey.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.5.1+cvs20040105i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 04, 2004 at 05:19:26PM -0800, dean gaudet wrote: > On Thu, 4 Mar 2004, Jean-Luc Cooke wrote: > > > recommend using a MAC with CTR. (Why still have CTR? Unlike CBC, you can > > compute the N+1-th block without needing to know the output from the N-th > > block, so there is the possibility for very high parallelizum). > > for disk crypto there are other opportunities for parallelism using > bitslicing to encrypt/decrypt multiple blocks in parallel (for example see > ). there's a > latency/throughput tradeoff though... Humm. Though AES uses GF's a lot, I think on 32bit processors bit slicing AES just isn't worth it. Though 512 byte fs blocks would only take 16 "transforms". It's really hard to implement ShiftRow() in bitwise SIMD...and x86 cpus simply don't have enough registers (aliased or otherwise) to do this I think. Fun read though! JLC - bit-slicing MD5() will not improve things either, tried that for MD5CRK -- http://www.certainkey.com Suite 4560 CTTC 1125 Colonel By Dr. Ottawa ON, K1S 5B6