From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 21 Aug 2001 14:43:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 21 Aug 2001 14:43:01 -0400 Received: from abraham.CS.Berkeley.EDU ([128.32.37.121]:59910 "EHLO paip.net") by vger.kernel.org with ESMTP id ; Tue, 21 Aug 2001 14:41:46 -0400 To: linux-kernel@vger.kernel.org Path: not-for-mail From: daw@mozart.cs.berkeley.edu (David Wagner) Newsgroups: isaac.lists.linux-kernel Subject: Re: [PATCH] let Net Devices feed Entropy, updated (1/2) Date: 21 Aug 2001 18:38:33 GMT Organization: University of California, Berkeley Distribution: isaac Message-ID: <9lu9r9$n5v$9@abraham.cs.berkeley.edu> In-Reply-To: <3B80EADC.234B39F0@evision-ventures.com.suse.lists.linux.kernel> <20010820211107.A20957@thunk.org.suse.lists.linux.kernel> <200108210136.f7L1aa008756@vindaloo.ras.ucalgary.ca.suse.lists.linux.kernel> NNTP-Posting-Host: mozart.cs.berkeley.edu X-Trace: abraham.cs.berkeley.edu 998419113 23743 128.32.45.153 (21 Aug 2001 18:38:33 GMT) X-Complaints-To: news@abraham.cs.berkeley.edu NNTP-Posting-Date: 21 Aug 2001 18:38:33 GMT X-Newsreader: trn 4.0-test74 (May 26, 2000) Originator: daw@mozart.cs.berkeley.edu (David Wagner) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andi Kleen wrote: >It is not that they are hard to fix; e.g. a $10 sound card >with a noise generating circuit on input and a small daemon to feed >/dev/audio to /dev/random can do it; [...] This is a good idea, but do note that you have to be a little careful: there are lots of ways that the result can look random enough to fool /dev/random's entropy count but be non-random enough to provide much less entropy than you'd otherwise expect (e.g., 60Hz effects, etc.). I think it's a workable approach, and I warmly recommend using a broad diversity of entropy sources (including, e.g., soundcards), but you just have to be careful to avoid some of the pitfalls.