Graham Toal writes:
By the way, the reason I've never discussed the ecash threads on this group is because it was obvious right from the start that double-spending makes the schemes unworkable, and that only a central reference authority could patch the system to make it work, which (in my seldom humble opinion) entirely negates the point of these schemes.
Nope, not "entirely." Anonymity is still preserved, through the "blinding" operation, even when a clearinghouse approach is used. That is, the bank can assure itself that it issued the original note, even though the note presented to it cannot be correlated to the issued note. This is the breakthrough Chaum and others achieved. Anonymity (or untraceablility by Big Brother and Big Mother) is achieved, which is the major point of digital money. The possible need for online clearing is not a fatal flaw. A good place to read about this is the November 1985 "Communnications of the ACM" journal, in Chaum's cover article "Transaction Systems to Make Big Brother Obsolete." (Chaum has updated the article since, and newer versions can be found in various places.) --Tim May -- .......................................................................... Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay@netcom.com | anonymous networks, digital pseudonyms, zero 408-688-5409 | knowledge, reputations, information markets, W.A.S.T.E.: Aptos, CA | black markets, collapse of governments. Higher Power: 2^859433 | Public Key: PGP and MailSafe available. "National borders are just speed bumps on the information superhighway."