Re: GAK

>
>If too much attractive stuff is available by loss of any one public key,
>that key gets attacked.  To compensate for this, the TIS DRC generates new
>public keys periodically to give out to new (or old) customers.
>
>However, a government warrant which demands the DRC's private key collection
>would gain quite a harvest.

The economics of the situation seem to dictate that whether you have
one key or N keys, it's going to be cheaper to subvert the escrow agent
(you guys or whoever) than it is to brute-force even one key. Therefore
I'm not clear on how using multiple keys buys you much against the most
probable threat -- opponents getting physical access to keys or the
subversion of personnel who have legitimate access.

Of course, it's still a good policy, reducing the payoff to those too
timid to try the direct approach. But I think this threat is significantly
less likely than a disgruntled employee selling the DRC private
keys on a real instantiation of the Blacknet model, without even being
solicited.

You may feel very comfortable with the personnel and procedures you
have in place now, but auditing and vetting systems are notorious
for scaling very, very poorly. You may feel you can vouch for the
trustworthiness of everyone at TIS now, but this sort of familiarity
also scales very poorly. And clearly, were this to become commercially
significant, it would need to scale quite a bit.

Douglas Barnes
Electric Communities

>Date: Fri, 8 Sep 1995 17:58:57 -0800
>From: cman@communities.com (Douglas Barnes)
>
>
>>
>>If too much attractive stuff is available by loss of any one public key,
>>that key gets attacked.  To compensate for this, the TIS DRC generates new
>>public keys periodically to give out to new (or old) customers.
>>
>>However, a government warrant which demands the DRC's private key collection
>>would gain quite a harvest.
>
>The economics of the situation seem to dictate that whether you have
>one key or N keys, it's going to be cheaper to subvert the escrow agent
>(you guys or whoever) than it is to brute-force even one key. 

You're right, of course.  That's why I, personally, would trust my key
backup only to (k of n) TIS DRCs in Earth orbit or farther out.

>You may feel very comfortable with the personnel and procedures you
>have in place now, ....

People keep assuming that TIS will run a commercial DRC.  We do not plan
to.  We did the design and will sell DRC hardware and security consulting
(physical, policy, ...) to companies wanting to set up their own for
internal use.  That's the only mass DRC market we envision.  This could
change, but that's the current plan.

Meanwhile, the real question is GAK -- whether the DRC you choose to use
goes along with it or not.  You might check my home page for my views on
GAK.  It is possible to have a Corporation running a DRC which refuses to
play along with GAK.  They won't be blessed for attachment to exportable
crypto, most likely, but it's entirely possible for this to exist.  Tim May
may run one, for example.  (I'd still want it to be in orbit.)

 - Carl

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