Intel to include DRM in new Pentium 4 series processors

[Brian Gladman]

From: "Ken Brown" <k.brown@ccs.bbk.ac.uk>
To: <ukcrypto@chiark.greenend.org.uk>
Sent: Friday, September 13, 2002 6:43 PM
Subject: Re: Intel to include DRM in new Pentium 4 series processors


> Brian Gladman wrote:
> [...]
>
> > > Based on this I don't see how anyone can promise that the hardware
> > > owner will _always_ be able to load any key he wishes.
> >
> > Of course not - in a trivial case the secure store may be full.  But in
> > priciple the PC owner has full control over TCPA key management
features.
> >
> > However, once an owner allows a remote agent to 'rent' a secure box on
their
> > machine, they won't necessarily know what is goes on inside this box AND
> > they won't necessarily know what their machine is doing when it is
running
> > software designed to run in association with this box.
> >
> > This seems to me to be an incredibly stupid thing to allow on a machine
that
> > any owner wants to continue to trust.  I take the view that as soon as
my
> > machine runs _any_ software for which I do not know the functionality, I
> > have then lost any ability to trust what my machine does from this point
on
> > (at least on current machines). And for me this means that TCPA DRM
features
> > may allow a remote agent to place more trust in a machice but they do so
at
> > the expense of the ability of the owner's trust in it.
>
> But who is to say that the "owner" of a machine, in the TCPA sense, is
> the human being who paid money for it in the shop?

Of course as a PC buyer you can always be ripped off by an unscupulous
vendor and nothing TCPA does can stop all forms of scam that you might be
exposed to.

The TCPA sub-system can be reset to a naked state that is guaranteed by the
_module_ provider so when you purchase a PC and wish to use its TCPA
features I would expect you to reset it to this initial state  There is then
a 'take ownership' command available for you to do what it suggests. This is
involves a window of vulnerability in time during which careful physical and
electrical safeguards need to be observed.  And after this period the
machine will need physical protection in order to prevent a reset (although
there are backup procedures for critical data items).

Of course the next question is "can I be ripped off by the module supplier'
and the answer is again "yes".  I would have preferred TCPA module designs
should be subject to open scrutiny but I know that this is not going to
happen (although I am continuing to push for this).  Hence I have settled
for access under NDA to some designs and I will make public observations
about my views on them when the time is right.   I am sure others are doing
the same.

Several of the TCPA derivatives are truly impressive and I am amazed at the
ambition shown by some suppliers and the security value they hope to offer.
As a person with an interest in good security it will be the emergence of a
TCPA machine that will lead to my move from Windows to GNU/Linux since TCPA
hardware security features combined with Free/Open Source software will
provide me with an order of magnitude improvement in security compared with
what I have now.

Closed Source software can never provide security except through blind faith
in the supplier and Open Source software without hardware support is very
little better since anyone can compile all sorts of illicit functionality
into it. But Free/Open source software with hardware security support can
provide a way towards security improvements in my view.

I might even use the secure box features to allow others I trust to have
secure boxes on my machine but I don't expect to allow any companies (other
than, possibly, my bank) to use this facility. In other words my use of
these facilities will be in secure key negotiation, not in DRM.

> What prevents hardware suppliers teaming up with content providers to
> sell (or rent) machines that are programmed to only read files supplied
> by them and which regard the software supplier as the "owner"?  So a
> computer that can only play Disney-approved films or whatever. (Or
> Sa'udi approved music, or CIA approved news broadcasts)

Nothing other than market pressures stops this now and I don't see TCPA
changing this in principle.  However, as I have already said, market
distortion caused by TCPA is an issue.

    Brian Gladman