From owner-freebsd-arch Sat Jul 22 7:14:42 2000 Delivered-To: freebsd-arch@freebsd.org Received: from localhost (localhost [127.0.0.1]) by hub.freebsd.org (Postfix) with ESMTP id 0B9EA37C34D; Sat, 22 Jul 2000 07:14:37 -0700 (PDT) (envelope-from green@FreeBSD.org) Date: Sat, 22 Jul 2000 10:14:35 -0400 (EDT) From: Brian Fundakowski Feldman X-Sender: green@green.dyndns.org To: "Louis A. Mamakos" Cc: Kris Kennaway , arch@FreeBSD.ORG Subject: Re: Quantifying entropy In-Reply-To: <200007220539.BAA61106@whizzo.transsys.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sat, 22 Jul 2000, Louis A. Mamakos wrote: > > Another source of noise could be via the RF tuner in a video capture > baord. You could get plenty 'o noise on both the audio output as > well as the noisy video fields when tuned to an unused channel. Remember that this approach is easily subverted. An attacker can compromise your entropy by detecting what frequency you are tuned to and attack that frequency with predictable data. A protection to this would be a good implementation of a spread-spectrum and spectrum-hopping RF tuner, but then you're relying on its PRNG for the data, really, and if it were that good you'd want to use it anyway ;) > louie -- Brian Fundakowski Feldman \ FreeBSD: The Power to Serve! / green@FreeBSD.org `------------------------------' To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message