On Sat, Dec 30, 2000 at 04:28:24AM -0500, dmolnar wrote:
I agree with you that the term is stretched a bit thin. Still, there seem to be at least two major things which fall under it in the work I've seen
1) "Digital Rights Management" - which you mentioned below 2) Contract languages like E (www.erights.org) and the Haskell combinator library discussed in
Simon Peyton Jones, Jean-Marc Ebert, and Julian Seward in ICFP 2000 ``Composing Contracts: an Adventure in Financial Engineering.'' http://riss.keris.or.kr:8080/pubs/articles/proceedings/fp/351240/p280-jones/... (thanks to Norman Ramsey for the reference)
Thanks for the reference - I'll look at it over the weekend.
Even so, it seems to me that their techniques will have wider application. Suppose Alice wants to selectively reveal parts of her contact with Bob to Carol -- maybe she wants to convince Carol that Bob didn't give Alice a better price than Bob did to Carol in order to win Carol's goodwill.
I have a hard time imagining this being useful in real life - I'm not interested in seeing only part of a contract, because I've got no idea what the rest of the contract says. The fact that there's language on one page which appears to set particular terms doesn't mean that the language is operative - perhaps it was prefaced with conditions which aren't presently applicable, or are now but won't be in the future. Or perhaps the contract has expired, or is void, or is voidable, or has been breached, or terminated. This seems pretty much exactly comparable to showing a programmer parts of a computer program and asking them to reach a conclusion about the behavior or correctness of the entire program, including the omitted or obscured parts. I can't imagine any sensible person who would act on a contract shown to them by someone else if the someone else refused to show them the entire document - but that's what's proposed in the scheme described in the Durfee and Franklin paper. They do discuss being able to prove (instead of guarantee) that certain terms of the license (which they insist on calling a contract) are within the boundaries of a pre-existing master "contract", which is a good beginning, but they're avoiding a lot of the hard work by assuming that every important term can be represented as a single value, and ignoring the interrelationships between terms or values. For example, "This license is terminable on 30 days' notice at licensor's option if the royalties paid in any calendar year are less than $10,000.00 USD." isn't an uncommon term in a license agreement - how is a sublicensor to prove to a prospective sublicensee that the license hasn't been terminated? They'd need to prove a negative - nonreciept of the notice of termination - which is notoriously difficult. (The middleman could produce proof tending to show that they had not breached, leading to the inference that notice, if given, would have been inappropriate - but that's not the same result.)
The techniques in the paper seem to allow Alice to do that without having to reveal exactly what her price from Bob was (or learn what Carol's price was, for that matter) -- and have it backed up by a contact signed by Bob.
Then again, I don't know how often these kinds of situations come up in real life...or will come up in the future.
My hunch is that it won't - I do still think it's a neat trick, but it sounds a lot like a solution searching for an applicable problem, instead of the other way around.
Where would I go to learn about the difference between contracts and licenses so as to understand what you mean here? (Besides law school; that's still an option for me, but not now). Because I'd like to avoid contributing to this problem if that's possible...
If you are in the mood to read, "Understanding Copyright Law" by Marshall Leaffer is about $30 and hopefully accessible; my favorite reference for contract law is Farnsworth's "Contracts" hornbook, though I fear it may not be as friendly to people who don't have a compelling reason to make their way through it. I am having a hard time thinking of a good way to learn what the books don't explain, which is how to figure out which body of law is applicable to a given problem. I am only getting better at that some 5 years out of law school, and it's not even something where experts agree. Questions about how to organize transactions to minimize the incidence and consequences of failure are very old questions, and legal and insurance people have evolved some pretty detailed approaches to solving common (and uncommon) problems - it's something of a waste of time for people to start working on those problems without learning about what's been tried in the past. That certainly doesn't mean that what's done now is perfect, or efficient - but in many cases it's been shaped by tens or hundreds (or maybe thousands) of years of experience and testing, which does have some value. Mostly I think it's unfortunate that relatively common words like "signature" or "contract" get reused - initially it's not a big problem, because the people close to the theoretical work understand the gulf between their models and the real world - but 5 or 10 years out, we end up with questions like "are digital signatures really signatures" or "is a smart contract a contract" or "do you mean you signed it with a pen, or with your browser?". I guess this is the same process that called cars "horseless carriages" for awhile - people who think of new technologies name them after older things which serve many of the same goals, leading to confusion. That doesn't seem so terrible, but I do think that the "smart contracts" trend ignores the real role of contracts, which is their social role - which is that they're agreements which society will force people to fulfill, not agreements enforced by technology. Both the DRM and the E-rights technologies assume that there can be no meaningful external review of the agrements or the actions of the parties to an agreement, and proceed to limit people's behavior accordingly. That may be a reasonable assumption to make - but it is not law, at least in the way that people talk about "the rule of law". It does limit human behavior - which is the purpose of law - but it does it in a different way (the same way that fences or handcuffs do). Larry Lessig's book "Code" talks a lot about how technology can create its own limits for human action, though I think it's unfortunate that he calls it "law". In any event, it's confusing to a lot of people to mix those two approaches to governing human conduct (or human conduct as expressed through machines) - one consists of verbal expressions which are interpreted by human beings (where that interpretive process may be recursive), another consists of physical things which need or permit no interpretation (though they may contain Turing machines). My own interests and biases lean towards the former model (though I am not such a purist that I refuse to employ locks or guns if necessary), but the second model is also certainly legitimate. My real beef is with people who accidentally or deliberately confuse the two models, because that leads to unproductive thinking and behavior. -- Greg Broiles gbroiles@netbox.com PO Box 897 Oakland CA 94604