Ideal digital cash system?
-----BEGIN PGP SIGNED MESSAGE----- On page 123 of Applied Cryptography Bruce Schneier cites the work of two cryptographers and the digital cash system they invented that satisfies all six properties he listed on the same page. In his words: The authors consider this the first ideal untraceable electronic cash system. The reference [674] is: T. Oamoto and K. Ohta, Universal Electronic Cash Advances in Cryptology--CRYPTO '91 Proceedings Berlin: Springer-Verlag 1992 pp. 324-337 Is anyone here familiar with this work? Has anyone tried to implement this protocol in some manner? Also how would I go about obtaining the text of this work either in written form or online? ======================================================================= Johnathan Corgan "Violence is the last refuge of the incompetent" jcorgan@netcom.com -Isaac Asimov PGP Public Key: http://www-swiss.ai.mit.edu/~bal/pks-toplev.html Or send email to: pgp-public-keys@pgp.ai.mit.edu Subj: GET jcorgan ======================================================================= -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBLuVcyU1Diok8GKihAQGuIwP+KaH0arHX1MADCi+KHMWjSCq3VNoUR1O1 aIBagedXbegdXmzkcmdTebgfKYQKpZN3Ple8Bt1k3KzXepS/gcIZUGWeN7P5c+tC 2/zFbTLYhl+BCjZpRZ2PnxTZWYASUYoKnZ1sXeh18bYPxtR+g9BSCmleau1W5d/g yAi2QSuxdBg= =gTBc -----END PGP SIGNATURE-----
Johnathan Corgan <jcorgan@netcom.com> writes:
The authors consider this the first ideal untraceable electronic cash system.
T. Oamoto and K. Ohta, Universal Electronic Cash Advances in Cryptology--CRYPTO '91 Proceedings Berlin: Springer-Verlag 1992 pp. 324-337
(This should be Okamoto & Ohta.) This paper is not available electronically as far as I know. The crypto proceedings can be found in good university libraries. I believe the Okamoto scheme has the problem that payments by a person are all linkable. Basically when you open an account with the bank you get a "license" number B which you keep for all the time (and which the bank doesn't know). But every time you spend you have to send B. So all of the payments from a person will use the same B. True, this doesn't reveal his identity, but it allows a given pseudonym's spending patterns to be recorded and studied, which may be almost as bad. Okamoto forgot unlinkability in his laundry list of ideal cash characteristics. Hal
participants (2)
-
Hal -
Johnathan Corgan