On Tue, 9 Apr 2002, Adam Back wrote: > You can't outright counterfeit technically as the recipient of each > coin checks that it's correctly formed, and authenticated by the bank, > and that the chain of spends are all bound together. By doing this > the user is assured that either the coin will not be double-spent, or > the bank will identify the double spender when the coin is deposited. > > You might reasonably expect the bank to deal with double-spending > itself and give the depositor fresh money regardless of double spent > status.
In this case "double spending" and "counterfeit" are the same thing - you can spend the same coin 1000 times in a few seconds. As anonymous points out, it can be from half way across the planet too. Banks aren't going to deal nicely with double spent coins, they can't afford to. > If you use the normal approach of putting the identity in the coin, > you can't double-spend anonymously. But it's not until the coin goes back online, you need the minter's secret key to decode the chain (maybe I have that wrong?). > Building up technology trust is harder yes. But that I guess is > largely marketing and reputation. Most people probably don't > understand the security mechanisms in place with credt-cards either > (PIN offset on card etc.), or even more the more secure smart-card > based credit cards used in some parts of the world. I was thinking about this a bit while drifting off to sleep last night. It'd be cool to have electronic paper bills - flexable/cloth electronics where the value of the bill is variable. At each transaction, the bill reduces the amount it has (plain old smart card stuff) but it'd have the look and feel of paper money. the transaction machines that work with the bills would all need to be online, but you could easily trade bills for anonymous barter. It might even be easy to have a reader that just tells how much is left in the bill. The point here isn't technology, it's psycology. The bill "looks" like money, so people will trust that it is :-) Patience, persistence, truth, Dr. mike
