Jonathan Rochkind <jrochkin@cs.oberlin.edu> writes:
Physical cash works that way too; if I write down the serial numbers of all money that goes through my hands, then if it ever comes back into my hands I'm going to recognize it. It would be nice if ecash could not have this "flaw", but it doesn't seem vital, or even particularly important, to me.
OK, but one of the main characteristics of electronic cash is its anonymity. If we don't care about serial numbers we can just use an RSA-signed message from the bank saying "I'm worth $1.00" as the cash (at least in an on-line system). The whole reason we go through the blinding rigamorole is to make it so that the cash is unrecognizable after transfer. That is why I keep raising the issue about recognizability. You are probably right that most people wouldn't care, though. Hal