full-disk subversion standards released

[Peter Gutmann]

Ben Laurie <ben at links.org> writes:

>Apart from the obvious fact that if the TPM is good for DRM then it is also
>good for protecting servers and the data on them,

In which way, and for what sorts of "protection"?  And I mean that as a 
serious inquiry, not just a "Did you spill my pint?" question.  At the moment 
the sole significant use of TPMs is Bitlocker, which uses it as little more 
than a PIN-protected USB memory key and even then functions just as well 
without it.  To take a really simple usage case, how would you:

- Generate a public/private key pair and use it to sign email (PGP, S/MIME,
  take your pick)?
- As above, but send the public portion of the key to someone and use the
  private portion to decrypt incoming email?

(for extra points, prove that it's workable by implementing it using an actual
TPM to send and receive email with it, which given the hit-and-miss
functionality and implementation quality of TPMs is more or less a required
second step).  I've implemented PGP email using a Fortezza card (which is
surely the very last thing it was ever intended for), but not using a TPM...

>Mark Ryan presented a plausible use case that is not DRM:
>http://www.cs.bham.ac.uk/~mdr/research/projects/08-tpmFunc/.

This use is like the joke about the dancing bear, the amazing thing isn't the 
quality of the "dancing" but the fact that the bear can "dance" at all :-).  
It's an impressive piece of lateral thinking, but I can't see people rushing 
out to buy TPM-enabled PCs for this.

Peter.

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