peter honeyman writes:
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 could refer to observer based protocols. I don't see anything in the above paragraph to indicate that they have invented a digital coin. I don't see how offline non-observer based cash could possibly work. (e.g. I send a copy of my cash to someone in Europe and we "spend" them simultaneously) -- Ray Cromwell | Engineering is the implementation of science; -- -- EE/Math Student | politics is the implementation of faith. -- -- rjc@gnu.ai.mit.edu | - Zetetic Commentaries --