Is Off-Line Digital Cash Dead?

[bill.stewart@pleasantonca.ncr.com +1-510-484-6204]

Different businesses have different attitudes toward off-line cash
and similar things.  For instance, Bart/Metro magnetic subway tickets,
and the similar scrip that supposedly is popular in Japan
are all semi-electronic money, half-offline (don't know if the subway
tickets get reported to central locations or if all the processsing
is done locally...), and yet there's nothing more than honesty and
the technical difficulty of forgery that keeps them from being forged.
Postage meters are also off-line, and unlike subway rides,
which are hard to make lots of money accumulating (:-),
mail-oriented businesses could save lots of money using fake ones.

The main similarities I see between the above kinds of money
is that they're mainly issued, either directly or indirectly,
by the providers of specific services, and they're hard to use for
other kinds of service.  Since they use physical tokens,
though they may have digital information on them, they're obviously
hard to email across the internet, but anybody you can send email to is
already online...

As I see it, there are three main reasons for wanting offline cash -
- avoiding the need to wire your cash register equipment
- avoiding the per-event communication costs for the transaction
- avoiding the time delay for the communication

Per-event costs may be low, but in the non-wired world they're non-trivial.
A phone call typically costs at least one message unit, say 5 cents.
A CDPD cellular packet, according to some pricing I've seen, is similar.
That's not much money when you're selling cars, but it's a lot for newspapers.

Here at the former National Cash Register company, we've found that
retail stores really like wireless communications to the cash register;
in stores without datacomm wiring, it means you don't need to install any,
and even if there's wiring in place, being able to move point of sale
terminals around can be worth a lot, and if you only have to find
a location with AC power wiring and not data, you're more flexible.

The time delay for credit card verification is also an issue -
modem-based systems typically take 15-20 seconds, while on-line
systems take 2-3 seconds when the network isn't busy.
That's an important issue at a retail store, when you can spend the
transaction time putting merchandise in bags - it's far more
important for things like road tolls or subway turnstiles.

And waiting three days for your remailer network to bounce back
an acknowledgement on your retail cocaine transaction will just _not_ do :-)!

If you can accomplish all these successfully with offline systems, great!
Too bad it's hard to do while retaining anonymity.

		Bill Stewart