Re: Chaum on the wrong foot?

[peter honeyman <honey@citi.umich.edu>]

yes, i am replying to a message that is six weeks old.

hal, chaum may be barking up the wrong tree, but that doesn't mean
that his students are.  i read a couple of digital cash papers last
night and was struck by this statement in one of them:

    Techniques have been developed that ... allow the construction of
    off-line electronic cash systems that are secure for the bank, yet
    at the same time honest users of the system are guaranteed to
    remain completely anonymous.  This holds in a very strong sense:
    the security of banks is not compromised even if all users and
    shops collaborate in such an attempt, and the privacy of honest
    users cannot be violated in any cryptanalytic way even under
    adversarial behavior of the bank in coalition with all the shops.

					  Stefan Brands, CWI

this is very encouraging: digital cash technology is very far advanced,
and offers almost everything you might want.  (i think the jury is
still out on the question of k-spendability.)  but then there is the
bad news:  the mathematics and the protocols underlying the technology
are still too complex to be practical.  but there is also good news:
much of the current work intends to simplify the protocols and to
lessen the computational requirements of digital cash systems.

	peter