Ross's TCPA paper

[Adam Shostack]

On Mon, Jun 24, 2002 at 08:15:29AM -0400, R. A. Hettinga wrote:
> Status:  U
> Date: Sun, 23 Jun 2002 12:53:42 -0700
> From: Paul Harrison <pth-02 at pacbell.net>
> Subject: Re: Ross's TCPA paper
> To: "R. A. Hettinga" <rah at shipwright.com>

> The
> important question is not whether trusted platforms are a good idea, but
> who will own them.  Purchasing a TCP without the keys to the TPM is like
> buying property without doing a title search.  Of course it is possible to
> _rent_ property from a title holder, and in some cases this is desirable.
> 
> I would think a TCP _with_ ownership of the TPM would be every paranoid
> cypherpunk's wet dream.  A box which would tell you if it had been tampered
> with either in hardware or software?  Great.  Someone else's TCP is more
> like a rental car:  you want the rental company to be completely responsible
> for the safety of the vehicle.  This is the economic achilles heal of using
> TCPA for DRM.  Who is going to take financial responsibility for the proper
> operation of the platform?  It can work for a set top box, but it won't fly
> for a general purpose computer.

In general, I'm very fond of this sort of ownership analysis.  If I
have a TCPA box running my software, and thinking that its mine, how
do I know there isn't one more layer?  Leave it off, and my analysis
is simpler.

I suspect that verifying ownership of the TPM will be like verifying
ownership of property in modern Russia: There may be a title that
looks clean.  But what does the mafia think?  What about the security
services?  There may even be someone with a pre-Bolshevik title
floating around.  Or a forgery.  Hard to tell.  It's annoying to have
one's transaction costs pushed up that high.

I can get very high quality baseline software today.  What I need for
my cypherpunk wet dreams is ecash, and a nice anonymizing network.
What I also need is that the general purpose computing environment
stay free of control points, in Lessig sense.


Adam


---------------------------------------------------------------------
The Cryptography Mailing List
Unsubscribe by sending "unsubscribe cryptography" to majordomo at wasabisystems.com