RE: Free Rootkit with Every New Intel Machine

Ian Farquhar writes:
> [Hal Finney wrote:]
> > It seems odd for the TPM of all devices to be put
on a pluggable module as 
> > shown here.  The whole point of the chip is to be
bound tightly to the 
> > motherboard and to observe the boot and initial
program load sequence.
>
> Maybe I am showing my eternal optimist side here, but
to me, this
> is how TPM's should be used, as opposed to the way
their backers
> originally wanted them used.  A removable module whose
connection to
> a device I establish (and can de-establish, assuming
the presence of
> a tamper-respondent barrier such as a sensor-enabled
computer case to
> legitimize that activity) is a very useful thing to me,
as it facilitates
> all sorts of useful applications.  The utility of the
original intent
> has already been widely criticised, so I won't repeat
that here.  

Would that basically be the same as a removable smart card
or
crypto token?  Those do exist and I agree that they have
many useful
applications.  However their purpose is somewhat different
from the TPM,
which is more specialized.


> It also shows those interesting economics at work.  The
added utility of
> the TPM module (from the PoV of the user) was marginal
at best despite
> all claims, yet it facilitated functionality which was
contrary to
> most user's interests.  The content industry tried to
claim that the
> TPM module would facilitate the availability of
compelling content -
> which they tried to sell as it's user utility - but
like most of their
> claims it was a smoke and mirrors trick.

At this point we are reduced to speaking hypothetically. 
The TPM has
not provided either much benefit or much harm so far.  It
has not (AFAIK)
been used to protect any content, for good or evil.  It has
instead only
been used as a sort of glorified, non-removable smart card,
which indeed
does not provide much utility.


> Consequently, the razor-edged economics of the
motherboard and desktop
> industry has comprehensively rejected TPM except in
certain specialized
> marketplaces where higher profit margins are available
(eg. Servers,
> corporate desktops).  The chipset manufacturers have
also failed to add
> this functionality to their offerings to date.
>
> Now Vista has added Bitlocker, which arguably adds a
user valuable feature
> for which a TPM module is needed (yes, you can run it
without TPM, but
> it's painful).  I wonder if we'll start to see more
"TPM connectors"
> appearing, or even full TPM modules on motherboards and
cores on south
> bridge dies?

I think the focus is likely still to be on laptop systems
where the
benefits of an encrypted file system are especially high. 
However if
Bitlocker comes down to the lower level Vistas then we may
see TPMs
start to appear on lower end laptops.


> Personally, I'd like to see a TPM implemented as a
tamper-respondent
> (ie. Self-powered) module mounted on the motherboard in
a socket which
> allows removal detection.  That way you get the
flexibility of moving
> the module, with the safety of a programmed response to
an unauthorized
> removal.

Interesting idea, although it's not clear what you would do
with it.
The TPM architecture is enormously complex but it is
entirely focused
on binding a TPM to a platform.  Breaking that rule would
invalidate so
much of the TPM design that you might do better starting
with a new chip
with its own functions and purpose.

Hal Finney

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