From owner-freebsd-security Fri Oct 17 11:02:23 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id LAA26371 for security-outgoing; Fri, 17 Oct 1997 11:02:23 -0700 (PDT) (envelope-from owner-freebsd-security) Received: from smtp03.primenet.com (smtp03.primenet.com [206.165.5.84]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id LAA26360 for ; Fri, 17 Oct 1997 11:02:15 -0700 (PDT) (envelope-from tlambert@usr06.primenet.com) Received: (from daemon@localhost) by smtp03.primenet.com (8.8.7/8.8.7) id LAA10124; Fri, 17 Oct 1997 11:02:02 -0700 (MST) Received: from usr06.primenet.com(206.165.6.206) via SMTP by smtp03.primenet.com, id smtpd010107; Fri Oct 17 11:01:56 1997 Received: (from tlambert@localhost) by usr06.primenet.com (8.8.5/8.8.5) id LAA15510; Fri, 17 Oct 1997 11:00:35 -0700 (MST) From: Terry Lambert Message-Id: <199710171800.LAA15510@usr06.primenet.com> Subject: Re: C2 Trusted FreeBSD? To: haskin@ptway.com (Brian Haskin) Date: Fri, 17 Oct 1997 18:00:35 +0000 (GMT) Cc: mike@smith.net.au, freebsd-security@freebsd.org, softweyr@xmission.com, tlambert@primenet.com In-Reply-To: <344420F8.E4B912C7@ptway.com> from "Brian Haskin" at Oct 14, 97 09:48:40 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-freebsd-security@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > I believe that Mr. Peters is confusing the standard for erasing > something that has been written to disk with this. Although you can do > the same with ram (as far as recovering previously stored information) I > don't think that they make you write over it a hundred time for each > malloc free sequence. I think he was more paranoid about RAM backed by disk -- swap, in other words. I can see where you must treat freed swap pages as if it were freed disk space, including directional hysteresis based pattern erasures. I am much less concerned with things like flash cards; the IBM patent cited does not really relate to smart cards this way, since there is no hysteresis. If there is a quantum effect that is somehow measurable beyond normal background temperature fluctuations, I would think it would only apply in supercooled environmnents: like those in which you can use SQUIDs and MASERs. That said, you'd at least need to zero persistent RAM... and if you can't distinguish it, then the other poster is right: you'd need to zero all pages befor you freed them for reallocation. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.