CDR: Re: Zero Knowledge changes business model (press release)

[David Honig]

At 05:59 PM 11/1/00 -0500, Adam Shostack wrote:
>
>Matt Blaze did some work on non-subvertable key escrow, where you
>escrow keys with random folks, and when you, or Uncle Sam, want the
>key, you announce that, and hope to get the key back.  Let me be clear 
>that this also is not what we're doing. :)
>
>| Strong crypto means the employee can put an invincible lock on the
>| corporate file cabinet.   This might mean that invincible locks are
>| not used in corporations.  A corporation might require that any
>| invincible physical locks be used in series, so the corp can get into the
>| files if the first lock stays locked.  That doesn't seem wrong
>| to me; and in meatspace two locks in series is obvious and no compromise
>| is made to either lock's design.
>| 
>| Maybe no escrow per se, but corp. data is duplicated and each copy is
>| encrypted by a person's bizkey and the corporate shared key for that
person.
>| Locks in series.
>| 
>| (Now, it may be 'sad' that ZKS has changed its bizmodel to service
>| businesses that need locks in series, but I'm only interested in
>| whether its rational to universally denounce any locks-in-series
>| architectures.)
>
>Thats not really it.  We're much more focused on layered locks than
>series locks.  I would worry a lot about the architecture you outline
>above being vulnerable to a whole slew of attacks on any one key,
>which means an N key system is at least N times as vulnerable.

I was suggesting using a split key, where it would take collaboration
amongst N of M board members to assemble the second corporate-backup
key.  These kind of redundancy schemes are brilliant. Tolerating
turncoats and car accidents.

Series + parallel padlocks has interesting properties.


>| >The "relevant legislation" language is the real kicker. 
>| 
>| Though this was elaborated on in a later reply, they really do need to
>| specify what they mean exactly (re Canada & 'consumer privacy') when
>| they say the nasty l-word in their public literature.  Any mention of the
>| law in crypto lit turns the stomache, puts the scanners on highest
>| sensitivity.
>
>When we say 'nasty l-word' you can assume we're refering to CALEA,
>RIP, and that sort of thing.  When we talk about legislative
>compliance, we mean complying with that whole slew of privacy laws.

Govt "privacy" laws are a subset of what you should be doing,
so more power to you, as they say.

>As to the hypothetical that Tim will ask, we'll work very hard to
>prevent laws requiring key escrow from coming into being.  

Your bodily fluids remain pure.

We spend
>time and energy maintaining relations with law enforcement in a lot of 
>places, explaining to them why we don't build in back doors.  

Please video and archive.  Taxpayers want to know.


And,
>suprisingly, when you go and talk to them, rather than hissing and
>shouting, they listen.
>
>Adam

Of course they do, they're adsorbing intel.  

Good luck,
dh