- From: Pat Hayes <phayes@ihmc.us>
- Date: Tue, 9 Mar 2004 11:08:11 -0600
- To: Patrick Stickler <patrick.stickler@nokia.com>
- Cc: "Pat Hayes" <phayes@ihmc.us>, <www-archive@w3.org>, <jjc@hplb.hpl.hp.com>, "ext Chris Bizer" <chris@bizer.de>
>On Mar 09, 2004, at 13:18, ext Chris Bizer wrote: > >> >>>Is it information, or better considered meta-information? Can the >>>provenance info be accessed separately from the graph itself? >> >>Yes. > >Here's where I think we need to make an important distinction between >"authoritative" qualification of a graph and third-party qualification >of a graph. > >It may be the case that an agent trusts certain third parties, and even >may choose to trust statements made about a graph by a third party over >statements made about the graph in the graph itself (e.g. the owner >of the graph specifies a higher accuracy percentage than the more-trusted >third party, or the owner of the graph doesn't explicitly state that the >graph is asserted but the third party does, etc.). > >Note that the ability to consider third party statements about a graph >still doesn't preclude the need for a bootstrapping mechanism, since, >after all, one has to determine the trust associated with the graph >containing those third party statements as well... Interesting thought. Let me modify my earlier suggestion, or maybe extend it. Asserting is publishing with a publishMode="assert" tag (if tag omitted, publication is assumed as a SW default, but legal tightness might require it). Alternatively, one can give a URI which points to another document which acts as a 'publication warrant'; this might for example record provenance information, give security key information, things like that. And it can be stored on a secure server somewhere, safe from harm, and providing a checksum to use as security against malicious changes to the warranted graph. The publication warrant should itself have a publishMode="assert" tag on it, and can refer to the original graph by name, and can assert in RDF that it is warrant for the named graph. This would be very hard to fake, and can easily be made exponentially harder by adding more warrant layers referring to even more secure sources of warrantability. The very fact that the warrant URI is in a secure namespace uses the Web to provide a high degree of security. Notice also that this entire thing can be set up without any publication actually happening until the publishMode property on the warrant is set, and changing this value can 'turn off' the publication; so this provides a kind of trusted-third-party control over assertion: if you hold my warrant, then you can un-assert my publications. Of course I can just not refer to your warrant, but then who is going to trust me? >>I see the trust layer more as an application domain for named graphs. >>So for defining named graphs we don't have to go too far. >> > >We at least seem to agree on this particular point. > >Cheers, > >Patrick > >(sorry, Pat, for being in a closer timezone to Chris and pre-empting >your right to first reply...) S'OK, I see this as a free-for-all in any case. One of the joys of email is that you can interrupt without actually interrupting, if you see what I mean. Pat >-- > >Patrick Stickler >Nokia, Finland >patrick.stickler@nokia.com -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32501 (850)291 0667 cell phayes@ihmc.us http://www.ihmc.us/users/phayes
Received on Tuesday, 9 March 2004 12:08:14 UTC