Here's a copy of a post I made to imp-interest@thumper.bellcore.com (among other reasons to refute Detweiler, who is on imp now promoting his "tag the criminals" agenda). I hope I've given a fair overview of some of the things we're interested in, but from a "pro-commerce" rather than "pro-cypherpunks" point of view. (I find the ends and means to be very similar, but the point of view is different. imp-interest is interested in pushing Internet commerce, not ideological agendas). -----------------------

1. Can anyone else come up with some other Internet commerce models?

You mentioned one of the original digital cash shemes. There are wide variety of offline (2-party transactions) and online (realtime connection of buyer & seller with bank) digital cash proposals, many by David Chaum, his students, and colleagues (cf. Eurocrypt and Crypto proceedings). Some of these can be implemented securely in software, without the need for smart cards or other kinds of physical security. (For example, one's own digital cash can be encrypted with one's own private key & passphrase, making it as difficult to rip off as any other form of electronic money). Also, Chaum has an interesting per-organization pseudonym/transferrable credentials system that could allow checking credit ratings without revealing identity. Another, much simpler concept, is "digital postage", where tokens would be sold per service provider, perhaps from physical stores or vending machines, or online in exhange for other tokens, or by a non-private means like credit card as long as there is a fluid market for such tokens. These would be much like the token cards used now in subways, copy machines, etc. Although this is not as general as digital cash, client software might allow a wide variety of tokens to be maintained and used automatically, and the basic software would be less complicated (the underlying security protocols easier to understand and implement purely in software).

2. Do you think that the IBS model is good?

(Forgive me if I'm misunderstanding the nature of Internet Billing Service; I'm basing my comments on your comparison of it to credit card billing). I'm very concerned that IBS and on-line checks would, like credit cards, lack privacy, allowing dossiers to be easily collected on customer buying patterns. Under such systems there would be incentive for those seeking privacy to spoof (eg by creating false credentials and/or credentialling agencies), as well as for those seeking to defraud to spoof. A good net commerce model should be able to deal with the fact that many Internet users can easily create pseudonyms, and credentials (digital signatures, etc.) for those pseudonyms, without demanding expensive, privacy-endangering "true ID" enforcement. Given the extremely messy legal environment with thousands of jurisdictions criss-crossed by the Internet, a basic principle of Internet commerce should be to minimize the need for legal intervention. Also I'm concerned about the vulnerabity of the IBS organization(s) themselves to corruption, which could sap or destroy an economy centered on such an agency. A good commercial model should be decentralized so that any such corruption can be quickly routed around, much like the Internet is built to route around node failures. With the efficiency of on-line software customers can "ping" banks, billing services, etc. by depositing money in a very fine-grained manner at a wide variety of such service providers, to determine which services are the most trustworthy. Extensive reputation records for these services can be accumulated, searchable on-line Consumer Reports. Thus I hope a wide variety of decentralized means of Internet commerce can be tolerated. Of the possible means, digital cash and/or pseudonyms with transferrable credentials seem the most attractive. They are complicated in raw protocol and software, but could present a simple conceptual interface for most users, and they don't demand that third parties, ie net culture, net user's software, and world politics be changed in in fundamental ways. Some sorts of changes might happen, but the goal of Internet commerce is not to predict them or bring them about or prevent them (we can't do those things any better than anybody else), but to set up Internet commerce without having to rely on major help or change on the part of third parties. Nick Szabo szabo@netcom.com