full-disk subversion standards released

[Ben Laurie]

Peter Gutmann wrote:
> 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.

If I have data on my server that I would like to stay on my server and
not get leaked to some third party, then this is exactly the same
situation as DRMed content on an end user's machine, is it not?

>  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...

Note that I am not claiming expertise in the use of TPMs. I am making
the claim that _if_ they are good for DRM, _then_ they are also good for
protecting data on servers.

>> 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.

I agree that it is more cute than practical.

-- 
http://www.apache-ssl.org/ben.html           http://www.links.org/

"There is no limit to what a man can do or how far he can go if he
doesn't mind who gets the credit." - Robert Woodruff

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