From: "Perry E. Metzger" <pmetzger@lehman.com>
Date: Wed, 26 May 93 16:51:42 PDT
To: cypherpunks@toad.com
Subject: Re: Digital cash issuess...
In-Reply-To: <9305262325.AA05097@soda.berkeley.edu>
Message-ID: <9305262351.AA20929@snark.shearson.com>
MIME-Version: 1.0
Content-Type: text/plain



Eric Hughes says:
> >As a consequence, our
> >cash system is much more efficient in both computation and
> >communication complexity than previously proposed systems."
> 
> I take this with a grain of salt; see below.
> 
> >In our opinion, the most interesting of
> >these is that the entire cash system (including all the extensions)
> >can be incorporated straightforwardly in a setting based on wallets
> >with observers, 
> 
> I am not surprised that they find this interesting; David Chaum has
> patented all the observer protocols.
> 
> Having read these protocols in the original, I can say this is not
> much of an advantage.  The observer protocols are tremendously
> expensive computationally.  Anything you build on top of it won't be
> any faster.

As I understand it, "observers" are built in to supposedly uncrackable
hardware built into a smart card -- and I'm not a big fan of the
notion that you can make hardware non-reverse engineerable...

Perry