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Re: Potential use case for opaque space bank: domain factored network st

From: Jonathan S. Shapiro
Subject: Re: Potential use case for opaque space bank: domain factored network stack
Date: Sun, 07 Jan 2007 14:13:14 -0500

On Sun, 2007-01-07 at 03:02 +0100, Pierre THIERRY wrote:
> Scribit Marcus Brinkmann dies 07/01/2007 hora 02:35:
> > The right question to ask is if there is a significant difference in
> > the harm that can result from such an arrangement if I am out of
> > control compared to when I retain control.  I believe that to be the
> > case.

PLEASE be SPECIFIC! Control over *what*!?

> I may not remember well the past debate, but did you already give facts
> supporting that belief? I'm not sure that opaque memory as we discussed
> it now can do any harm per se.

So far as I can tell, there is harm in both cases. The harm of the
"opaque memory" design is the possibility of non-transitive copy and
non-inspectable code.

The immediate harms of the "transparent memory" proposal are (1) a
requirement for hierarchy, which has been found in other systems to
inhibit or defeat the Principle of Least Authority (POLA). POLA has been
found to be a very effective architectural tool in achieving robust
system designs. (2) The apparent need to introduce a significantly more
complicated and more vulnerable resource management model (partitioned
resource types, a.k.a. network space banks) to handle as a special case
those places where opaque memory was desirable.

The larger harm of the "transparent memory" proposal is that we do not
(yet) have any comprehensive description of an overall system design
based on this model, and we certainly have no security design for it

I completely support Marcus in his view that the "transparent memory"
proposal is worth exploring, but in my opinion it would be irresponsible
to design this assumption into a widely deployed system until its
implications are more fully understood. My concern is that I do not see
the necessary design work occurring that would determine that. This may
be simply because that discussion is not occurring here.

Jonathan S. Shapiro, Ph.D.
Managing Director
The EROS Group, LLC
+1 443 927 1719 x5100

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