Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 17 Oct 1997 18:00:35 +0000 (GMT)
From:      Terry Lambert <tlambert@primenet.com>
To:        haskin@ptway.com (Brian Haskin)
Cc:        mike@smith.net.au, freebsd-security@freebsd.org, softweyr@xmission.com, tlambert@primenet.com
Subject:   Re: C2 Trusted FreeBSD?
Message-ID:  <199710171800.LAA15510@usr06.primenet.com>
In-Reply-To: <344420F8.E4B912C7@ptway.com> from "Brian Haskin" at Oct 14, 97 09:48:40 pm

next in thread | previous in thread | raw e-mail | index | archive | help
> 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.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199710171800.LAA15510>