This makes sense. Thanks. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Nicholas Weaver Sent: Thursday, April 30, 2009 5:59 PM To: DePriest, Greg (NBC Universal) Cc: Paul Jessop; Nicholas Weaver; alto; [email protected] Subject: Re: [alto] The origins of the piracy debate...
On Apr 30, 2009, at 2:19 PM, DePriest, Greg (NBC Universal) wrote: > Thanks to Enrico and Nicholas for providing additional background and > explanations. > > The key point of disagreement seems to be that adding a content > protection requirement to ALTO would "hugely complicate and compromise > the design of > ALTO." > > I'm not an expert in such matters, have very limited exposure to the > area, and can't help but wonder if that is, in fact, correct. > > Was there a serious investigation or did someone simply do a > back-of-the-envelope analysis. For me, its "Intuition backed up by a threat analysis and usage cases": We have legitimate uses which requires ID churn: its the only way to guarantee that a rebalancing is fresh. Especially since nodes churn all the time, and ALTO may not have notification when nodes leave. We have legitimate uses which require IDs to be arbitrary (rather than representative hashes): ALTO is not just for file distribution, but other P2P optimization (eg, optimizing for low latency for DHTs) where hashes don't have meaning. ALTO doesn't want to deal with particular P2P protocols, which all may have different representations of what data or blocks are. And doesn't want to deal with colliding namespaces from different P2P programs. Thus defining ID as a UUID or other opaque identifier means ALTO doesn't have to deal with these problems. We have legitimate uses which require IDs to be creatable at-will by any party: Otherwise, ALTO becomes an admission only system which limits utility. Yet all three decisions (allowing churn, opaque-data IDs, at-will ID creation) and there becomes an easy countermeasure to ANY system predicated on "block bad IDs", as long as that system has a slower response time than the P2P network you are trying to prevent optimizing its communication, and you can't do "only allow good IDs" if IDs are creatable at-will by any party. And "if a defense has a trivial countermeasure, don't bother deploying it". Thus this means the only way to make ALTO "content protecting" is to remove one of those three constraints. But all three features are very valuable in a localization service. Additionally, there is a large bias in the network community in general to be "content neutral". Any time you cease to be content neutral on the technical level, it must necessarily impose constraints and costs on the system. _______________________________________________ alto mailing list [email protected] https://www.ietf.org/mailman/listinfo/alto _______________________________________________ alto mailing list [email protected] https://www.ietf.org/mailman/listinfo/alto
