From: Matthew J Ghio <mg5n+@andrew.cmu.edu>
Is there a way of marking digital coins, so the depositor can be identified?
Only if the depositor marks them as such. The depositor generates the coin, and gives it to the bank to sign it. The bank signs it in exchange for another valid signed token. The bank can't alter it in any way, the bank can only sign it.
It's not the depositor who generates the coin, it's the withdrawer. Generally, he will be able to, in effect, "mark" the coin so that when it is deposited at the bank (by whomever he paid it to) the bank will be able to recognize that cash (because the withdrawer told the bank what the numbers were). However, with digital cash, it may be possible for the depositor to be anonymous and deposit the cash without being identified, so that even though the cash is recognized it does not necessarily reveal the depositor. Hal