Re: All our eggs in one basket?
Some of Jim's points can be addressed with existing protocols. When the bank sends you cash which you have withdrawn they would want to send it in such a way that they get a return receipt from you. That way they can prove you have received it. Schneier's book describes such a "digital certified mail" protocol in section 6.3 of his book, but it looks like it uses a lot of data. More concise implementations may exist. Other forms of cheating could be imagined. I could send cash to a company, and they could refuse to send me goods, but claim that they had done so. Or I could receive goods from a company, but claim that they never arrived. These could also be addressed with certified mail, either paper or digital, depending on whether the goods are physical or electronic. In an online system, the bank could refuse to accept a cash deposit, even though it was valid cash, claiming that it had already been deposited. To prevent this, the bank would have to record who made each deposit in the past and stand ready to reveal this information. A merchant could collude with the bank to provide forged deposit records to help with this scam. I don't see how to solve this one, but if it were done on a large scale people might become suspicious about the excess of apparent double-spending via a small number of merchants. The bank's reputation would suffer, as long as people found out about it. Perhaps customers should demand that banks publish statistics about (apparent) double-spending in order to detect this scam. Hal Finney hfinney@shell.portal.com
It seems we're worrying about something that is between a non-problem and a simple copy of an existing problem. Today we use paper cash and paper forms. I go to the bank to make a withdrawal, I fill out a paper form requesting money. They take the form, fail to give me cash, claim that I have been given cash. What recourse do I have? (Several is the answer, but the point is that it's not a problem new to digicash.) Today I order from a supplier. I send a paper form of payment (P.O., check, paper copy of my CC #, etc.). They cash such form and do not send me goods (or claim that they did and they were lost in transit). What recourse do I have? (Again, several. Again the point is that digicash does not seem to be introducing new problems; rather it's giving us new forms of old ones.) As a side note: one of the reasons I use credit cards (even though it gives a record of my purchases that can be used for marketing and other unintended purposes) is that the CC company does a large volume of business and guarantees my transaction. If I dispute a charge with the merchant, the CC company automatically takes my side. They take it out of the merchant's hide. Plus, since the merchant doesn't want to be in a bad way with a big customer (Visa, say) -- there is a huge incentive for him to make good, much more incentive than if he were dealing with me directly. For these reasons, I think that something like CC houses will still prosper under a digicash regime. --Alan Wexelblat, Reality Hacker, Author, and Cyberspace Bard Media Lab - Advanced Human Interface Group wex@media.mit.edu Voice: 617-258-9168, Pager: 617-945-1842 PUBLIC KEY available by request Try not to have a good time ... This is supposed to be educational.
participants (2)
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Alan (Gesture Man) Wexelblat -
hfinney＠shell.portal.com