---------- : From: bryce@digicash.com : To: David G.W. Birch <daveb@hyperion.co.uk> : Cc: Multiple recipients of <e$@thumper.vmeng.com>; cypherpunks@toad.com : Subject: Re: #E-CASH: PRODUCT OR SERVICE? : Date: maandag 15 juli 1996 15:36 : : : -----BEGIN PGP SIGNED MESSAGE----- : : I think it would behoove us all to clarify our terms. I call : Ecash(tm) coins "electronic cash" for several reasons. Ecash(tm) : has all of the following characteristics in common with : conventional cash, in descending order of importance: : : : 1. Unforgeability. Ecash(tm) coins have intrinsic value : because they are cryptographically impossible to forge. : forgery is possible in 'real life' and is possible in 'virtual life'(another discussion wright there). It all depends on the amount of control and need of insider knowledge to be able to crack a system. The existence of a system is defined by the possibility of a crack. : : : 2. Finality. Payments are cleared on the spot. No outstanding : payment obligations remain after a purchase. : You are from digicash aren't you? Isn't this the dutch experiment on Ecash?(could be wrong there). I've been asking around and it seems digicash is one system whilst it becomes more and more competitors(for example www.digipass.com). The main difference I've heard is the one about argument between customer and bank about the amount of money that was transferred from bank to ecash to the E-store. Digipass seems to be working with a code generator that includes the amount parameter in the algorythm that generates the code that is send back to the bank or whatever. : 3. Bi-directionality. Payers and recipients use the same : software and the same protocol. It is not necessary for : recipients to be specially trusted by the bank or by the payers. : The fact is, I think, that some major battle is going to take place on the grounds of ecash. We're going to have quite a lot of protocols and software used within different conglomerates of company's. Only time will decide with which protocol we are going to buy our pizza's. : 4. Privacy. The privacy of Ecash(tm) payers is mathematically : unconditional. : Just like the privacy of e-mail and the independance of the WWW once was. : 5. Composability. You can make large Ecash(tm) payments out of : a collection of smaller Ecash(tm) coins. This is in contrast to : a check-based system where you typically draw a check for the : exact amount and transfer only a single check. : You're wright, though I always seem to end up with fewer money than I thought I had at the beginning of each month : 6. Small payments. Ecash(tm) coins are cheap enough to use : that they are practical for small payments. : : (As a note, I do not use the word "micropayments" here, because : I am beginning to think that a good technical definition of : "micropayments" is "payments whose value is less than the cost : of using current electronic coins". This qualifies schemes like : Shamir's and disqualifies, well... current electronic coins.) : : : There might be other angles we should talk about here. : : : I think that the first quality is the defining one, technically. : : : So, could a knowledgeable person e.g. Mr. Birch tell us why : Mondex should be considered to be "electronic cash"? : : : And similarly I would like to hear an informed opinion about : why Ecash(tm) should not be considered "electronic cash". : I tend to agree that Ecash(tm) would be even _more_ cashlike : if it were cleared off-line, but I don't consider that : difference very fundamental. (_Any_ digital money based on : our current understandings will have to be cleared at a : central clearer eventually, since digital information is : perfectly copyable.) : : : Thank you for your correspondance. : : : Regards, : : Bryce : : Ecash 2.x Team : :  : : -----BEGIN PGP SIGNATURE----- : Version: 2.6.2i : Comment: Auto-signed under Unix with 'BAP' Easy-PGP v1.1b2 : : iQB1AwUBMepI/UjbHy8sKZitAQEiJwL/VnpQEHL1rOQ6Hm9JIEgAfCGjSKOPaIiC : Jp7EVjvPoFYEsQAS4iUWybNLpxi/23uaqpXMCSNMrEwqd8WeC5ZSISldIEK/BnYE : 2bULeAeMhIqm92bP6o64ok1NBGPfvK5X : =ANO4 : -----END PGP SIGNATURE-----