Minutes: XDI TC Telecon Friday 2011-08-05

[Drummond Reed <drummond.reed@xdi.org>]

Following are the minutes of the unofficial telecon of the XDI TC at:

Date:  Friday, 05 August 2011 USA

Time:  1:00PM - 2:00PM Pacific Time (20:00-21:30 UTC)

ATTENDING

Mike Schwartz

Markus Sabadello

Bill Barnhill

Joseph Boyle 

Drummond Reed

Les Chasen

THE GOTOMEETING FOR TODAY IS:

     https://www2.gotomeeting.com/join/969244355

THE IDEARPAD LINK FOR TODAY IS:

     http://xdi.idearpad.org/38

1) UPDATES

Drummond reported that on recent meetings he has had, there has been increasing interest in XDI in the personal data ecosystem space. The underlying reason is that this problem space requires universal addressability, data portability, and link contracts.

2) LINK CONTRACT POLICY EXPRESSION

Mike and Drummond reported on the breakthrough they reached regarding policy expression using just $and, $or, and $not, plus standard XDI !x and *x instance and ordering rules. This proposal is documented at:

    http://wiki.oasis-open.org/xdi/XdiPolicyExpression

There was a concensus that it was, like the XDI graph model itself, an example of reaching a point where it is clearly "as simple as possible but no simpler".

Discussion then turned to the question of rules expression syntax. Mike's proposal from several calls back is to use Javascript syntax. Bill pointed out the security issues involved with that approach, and Drummond agrees that it will be an issue with any environment that is concerned about security issues with Javascript interpreters.

Bill's suggestion is that rules expression should be part of the graph "all the way down to the end", i.e., the entire rule should be expressed in the graph. Drummond agrees that this is the purest approach that will eliminate any issues about either:

• Security issues due to "code in the graph"

• Implementation language restrictions or bias

Mike said that he understood the rationale for that approach but that would involve a lot more work to define the rules language

We had a very long discussion about the tradeoffs. Bill finally suggested that the link contract spec require a declaration of the rules expression language used in the link contract. There was general consensus about this approach because this way we can put out an initial spec that:

• defines Javascript as a rules expression language

• is open to other rules expression languages like XACML and KRL

• State that the TC plans to develop an XDI rules expression language that would be as portable and interoperable as XDI itself.

3) NEXT CALL

The next call is next week at the regular time. 

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ONGOING ISSUES LIST

Each of these is a candidate for the agenda for future calls.

* DO WE NEED SEPARATE METAGRAPH WORDS FOR EQUIVALENCE AND INVERSION? (added 2011-06-30 - Giovanni)

This is an open issue because algorithmic inversion does not have a direct corallary in RDF.

* SYNONYM HANDLING (added 2011-06-30 - Giovanni)

This remains an open issue because it raises challenges with compatibility with RDF.

* TRANSACTIONAL INTEGRITY FOR XDI (added 2011-03-24)

Since  versioning, as one example, involves multiple transactions that must be  commited as a group, we will need to address transactional integrity.  Specifically, we need to define how this will be handled at the protocol  level, vs. the implementation level.

* PROPOSED CONSTRUCTS/OPERATORS FOR XDI

Discuss the following wiki page originally posted by Giovanni:

  http://wiki.oasis-open.org/xdi/XdiNewFoundation

* DICTIONARY STRUCTURE

Mike would like an example of the PDX dictionary as soon as we can do it.

*   EQUIVALENCE SEMANTICS

Close on whether we need an additional $ word that is the equivalent

of Higgins Personal Data Model (PDM)  semantics of h:correlation,

which is not as strong as $is.

      http://lists.oasis-open.org/archives/xdi/201006/msg00036.html

* COOL URIS

Continue previous discussion about the use of standard RDF URIs in XDI:

  http://lists.oasis-open.org/archives/xdi/201006/msg00023.html