From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S275751AbTHOIKM (ORCPT ); Fri, 15 Aug 2003 04:10:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S275752AbTHOIKL (ORCPT ); Fri, 15 Aug 2003 04:10:11 -0400 Received: from dyn-ctb-203-221-74-26.webone.com.au ([203.221.74.26]:24583 "EHLO chimp.local.net") by vger.kernel.org with ESMTP id S275750AbTHOIKG (ORCPT ); Fri, 15 Aug 2003 04:10:06 -0400 Message-ID: <3F3C9523.7090903@cyberone.com.au> Date: Fri, 15 Aug 2003 18:09:07 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.3.1) Gecko/20030618 Debian/1.3.1-3 X-Accept-Language: en MIME-Version: 1.0 To: "David S. Miller" CC: Andries Brouwer , val@nmt.edu, daw@mozart.cs.berkeley.edu, linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH] Make cryptoapi non-optional? References: <20030809173329.GU31810@waste.org> <20030813032038.GA1244@think> <20030813040614.GP31810@waste.org> <20030814165320.GA2839@speare5-1-14> <20030815001713.GD5333@speare5-1-14> <20030815093003.A2784@pclin040.win.tue.nl> <20030815004004.52f94f9a.davem@redhat.com> In-Reply-To: <20030815004004.52f94f9a.davem@redhat.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org David S. Miller wrote: >On Fri, 15 Aug 2003 09:30:03 +0200 >Andries Brouwer wrote: > > >>On Thu, Aug 14, 2003 at 06:17:13PM -0600, Val Henson wrote: >> >> >>>entropy(x) >= entropy(x xor y) >>>entropy(y) >= entropy(x xor y) >>> >>Is this trolling? Are you serious? >> > >These lemma are absolutely true. XOR is the worst way >to gain entropy because it means that if you are able >to know anything about either 'x' or 'y' then you are >able to know something about the resulting entropy. > _Either_ x or y? Surely not! 1 ^ ? = ? you still have 1 bit of entropy.