From owner-freebsd-current Wed Jul 19 10:46: 8 2000 Delivered-To: freebsd-current@freebsd.org Received: from rover.village.org (rover.village.org [204.144.255.49]) by hub.freebsd.org (Postfix) with ESMTP id 1819F37B8C3 for ; Wed, 19 Jul 2000 10:46:03 -0700 (PDT) (envelope-from imp@harmony.village.org) Received: from harmony.village.org (harmony.village.org [10.0.0.6]) by rover.village.org (8.9.3/8.9.3) with ESMTP id LAA93117; Wed, 19 Jul 2000 11:46:01 -0600 (MDT) (envelope-from imp@harmony.village.org) Received: from harmony.village.org (localhost.village.org [127.0.0.1]) by harmony.village.org (8.9.3/8.8.3) with ESMTP id LAA82887; Wed, 19 Jul 2000 11:46:01 -0600 (MDT) Message-Id: <200007191746.LAA82887@harmony.village.org> To: Peter Dufault Subject: Re: randomdev entropy gathering is really weak Cc: current@FreeBSD.ORG In-reply-to: Your message of "Wed, 19 Jul 2000 09:08:36 EDT." <200007191308.JAA98111@hda.hda.com> References: <200007191308.JAA98111@hda.hda.com> Date: Wed, 19 Jul 2000 11:46:01 -0600 From: Warner Losh Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message <200007191308.JAA98111@hda.hda.com> Peter Dufault writes: : > The reason why ntp is interesting is that we compare the received data : > with our unpredictable local clock. It is the result of this comparison : > which is good entropy bits. : : Is the resolution of thermal sensors on many new motherboards and : CPU high enough to get thermal randomness? Yes. You'll also find that the voltage drifts as well. However, I doubt you'd be able to get more than 1 bit out of the voltage readings. The thermal readings, depending on their precision, would also yield several random bits. But this several may be only 3 or 4. The temperature varies based on work load and on the climate controls in place at the site. Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message