[OpenID] [foaf-dev] Can OpenID identify a person

[Lukas Rosenstock]

Am 07.06.2007, 17:02 Uhr, schrieb Dan Brickley <danbri at danbri.org>:

> Some SemWeb people (notably TimBL) take care to have a "non-Document"  
> URI for themselves, distinct from their homepages. eg.  
> http://example.org/foaf#memyself  ... but I don't know any usage of  
> these as OpenID URIs. In fact I don't know if an OpenID can have a  
> #hashblahblah section, or how that interacts with common OpenID tools,  
> services and practice.

This is impossible, because # defines a section of the document that is  
chosen locally and there can be only one declaration of an OpenID per  
document.

> It would be good if we could get confirmation from an OpenID expert that  
> it is reasonable to take OpenID URIs as (when used as URIs) naming  
> documents, and only indirectly being person identifiers.

I would say (imho) that not even inside the OpenID community we have a  
definite answer to that question. Technically, the goal of OpenID is  
merely to prove that the person who entered an URI is in control of that  
URI and the URI is nothing more than a means to find out the OpenID server.
People think differently about their OpenID. Some don't care what happens  
when the URI is loaded from a browser (maybe just a "This is an OpenID."  
message) because it's for authentication only. Others, like myself, think  
of their OpenID as their digital identity that can be used for  
authentication, for humans to find out information about me or contact me  
(through the browser) or for machines to do the same (FOAF/Microformats).

> To say that the URI "mailto:nadia at example.com" identifies both an  
> Internet mailbox and Nadia, the person, introduces a URI collision.  
> However, we can use the URI to indirectly identify Nadia. Identifiers  
> are commonly used in this way.

Good example: http://jyte.com/cl/danbri.org-is-an-author-of-foaf
Evan typed in: "http://danbri.org/ is an author of FOAF." (although it is  
clear that Dan himself and not his URI wrote the spec ...)

I'm CCing the OpenID-list, maybe someone else has a better answer on this  
issue.

> Various FOAF idioms (eg. use of primaryTopic and homepage properties)  
> can be used in RDF to make such "indirect identification" practice more  
> explicit. I think the "<foaf:Person><foaf:openid ..." design fits  
> reasonably well in that tradition, but I'm not an OpenID guru... (it  
> also allows more easily for multiple OpenIDs per person, tricky if you  
> use them as direct URIs, since owl:sameAs is too strong an assertion to  
> make to bind them together).

I like this design and would be happy to see it in the  FOAF spec soon.

Again I'm not an FOAF/RDF-guru, so would also something like  
<foaf:homepage rdf:resource="http://openid.net" foaf:is_openid="yes" />  
work?

Regards,
  Lukas

-- 
Lukas Rosenstock
Identity 2.0 Europe :: http://identity20.eu/