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Date: Tue, 14 Oct 1997 21:48:40 -0400
From: Brian Haskin <haskin@ptway.com>
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To: Mike Smith <mike@smith.net.au>
CC: security <freebsd-security@freebsd.org>,
        Wes Peters <softweyr@xmission.com>,
        Terry Lambert <tlambert@primenet.com>
Subject: Re: C2 Trusted FreeBSD?
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Mike Smith wrote:
> 
> >
> > There are no incidences in which pages are returned to you with
> previous
> > random cruft left in them?
> 
> There shouldn't be, no.
> 
> > And besides, zero-filling memory isn't sufficient, it has to be
> > overwritten a number of times to make sure now residual information
> can
> > be obtained.  These standards date back to core and even
> mercury-wire
> > memory.  Yes, I've actually worked with computers that feature
> *both* in
> > my career.  ;^)
> 
> If you can suggest how one goes about obtaining "residual" information
> from a saturated logic device in a synchronous memory subsystem, I'd
> be
> very interested in hearing it.
> 
> Or is this more specification paranoia?
> 
> mike

With an electron microscope and a few other pieces of similarily cheap
and nondestuctive equipment. :)

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.

Brian Haskin <haskin@ptway.com>