On Tue, 19 Dec 1995, Marcel van der Peijl wrote in the ecash mailing list:

...

Q: If user A signs up with bank A, and merchant B signs up with bank B, can user A buy at merchant B?

A: In theory:

Bank A and bank B need to have an interbank clearing agreement. User A sends his money to merchant B. Merchant B contacts his own bank, bank B. Bank B recognizes the money as being issued at bank A, contacts bank A, and clears the coins there. Bank A credits bank B's account at bank A, bank B sends an acknowledge to merchant B and merchant B sends the goods to user A.

On Fri, 22 Dec 1995, Patiwat Panurach <pati@ipied.tu.ac.th> replied:

I dispute this even on theoretical grounds.

Am I right in assuming that the only reason Bank B has in contacting Bank A is to confirm that the ecash hasn't been double spent? Once that is confirmed, there should be no need for contact between the two banks. Bank A should not have to credit Bank B's account as there has been no transfer from Bank A to Bank B. The transfer has been the deposit from

--------------------- I guess you mean: from Bank B to Bank A

Bank B's customer to Bank B. Bank B is allready "credited", i.e., its (e)cash researves have increased, the moment Bank A confirms that the ecash is valid.

In my understanding - and I'm sure Marcel van der Peijl :-) will correct me :-( if I'm wrong - the only way Bank B can verify with Bank A that the ecash it has received from merchant B has not been spent before is by actually sending the _coins_ to Bank A. Hence there _is_ a transfer from Bank B to Bank A and thus Bank A has to credit Bank B's account... Marcel? Ciao, leo _________________________________________________________________________ Leo Van Hove Centre for Financial Economics Vrije Universiteit Brussel (Free University of Brussels) Pleinlaan 2 B-1050 Brussels Vox: +32 2 629.21.25 Fax: +32 2 629.22.82 e-mail: lvhove@vnet3.vub.ac.be VUB's Web site: http://www.vub.ac.be _________________________________________________________________________