From: tcmay@netcom.com (Timothy C. May)
Date: Fri, 25 Mar 94 20:30:27 PST
To: cypherpunks@toad.com
Subject: Re: Digital Cash
In-Reply-To: <199403260412.XAA00321@orchard.medford.ma.us>
Message-ID: <199403260507.VAA02291@mail.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain



>    I have always been skeptical of this observer-chip approach, because it
>    wasn't clear that it was feasible to make a tamper-resistant chip
>    economically, and because the specialized hardware that would be
>    required would prevent the system from being used on widely-available
>    PCs.
> 
> Think "PCMCIA" here.. not just laptops, but now desktop systems and
> palmtop systems are starting to get PCMCIA slots these days.
> 
> 					- Bill

I have two devices that support PCMCIA-type slots: an Apple Newton and
an H-P 48sx (technically not a PCMCIA, but very close). In both cases
the slot is "spoken for" with memory cards.

I suspect this is the case with many of the laptops now beginning to
sport PCMCIA capability: the customers will not look kindly to having
to fill the slot of their whizbang laptop with a VISA or Digital
Express observer-chip card. Some may, and some will willingly swap
cards when the need arises (the newer PCMCIA cards allow
hot-socketing, i.e., removal while powered). Many won't.

The upshot: an observer-chip system predicated on having access to an
available PCMCIA slot will be a market failure, at least in the next
several years. (May be a moot point, as I see no move towards
observer-chip protocols happening anytime soon.)

Personally, I expect personal crypto dongles and/or similar gadgets to
be self-contained, in a wearable form. Maybe pendants, maybe rings
(real decoder rings!), maybe wristwatches. Communication will be by
inductive coupling or similarly robust links. (Inductive,
noncontacting transfer would allow implantation of the unit. IR
transfer through the skin is also possible.)

Little storage is needed for crypto keys, so the full capacity of a
PCMCIA card (tens of megabytes of flash memory, for example) is
overkill. An observer-chip system may need more storage, but not the
full capacity of a PCMCIA card of today. Hence, smaller size is
possible. Hence, wearable. Hence, always with the owner.

Just my view.


--Tim May


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Timothy C. May         | Crypto Anarchy: encryption, digital money,  
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