-- On 10 Dec 2001, at 16:16, georgemw@speakeasy.net wrote:
An idea just popped into my head, I was wondering if anyone had thought of this before. Most likely someone has, and has either proven the idea is impossible or has figured out how to do it.
Th idea is, when buying some good or service with digital cash, the customer first forwards the cash to the vendor in some transformed way such that the vendor can't yet spend it, but can verify that it is good cash of the correct amount, and that the customer will no longer be able to spend it.
The idea is, if the vendor follows through on his side, the customer will supply the additional information the vendor will need to redeem the cash. The customer can still rip the vendor off by refusing to do so, but he has no incentive, the money's already gone for him. Conversely, an unscrupulous "vendor" could in principle trick a customer into throwing away money on nothing, but he would gain no profit in doing so.
Vendor creates and blinds some tokens. Asks buyer to have them signed by money issuer. Money issuer signs them, and issues declaration that they have been signed. Buyer gives vendor the declaration, but not signatures. After delivery, gives signatures. --digsig James A. Donald 6YeGpsZR+nOTh/cGwvITnSR3TdzclVpR0+pr3YYQdkG vNpp48iuJszNXUqQ3P9/e7GUOEcHXoIDo33hfuKd 4xRG9QbdRJM31N1Lt+bhH55JK5VQWVorCJq0o7gAp