Subject: Re: [BH] Comments on draft-ietf-geopriv-reqs-03

From: John Morris <[email-masked]>
Date: Wed, 09 Apr 2003 18:05:00 -0400

Joe,

Let me offer my 2 cents in reaction to your comments.   Then, for the 
benefit of the "beyond http" P3P task force in the W3C (a new effort 
that I am just joining within the W3C), I will add at the end of this 
message my quick personal overview of where geopriv is now and where 
it is likely to go.  I encourage anyone on the  geopriv list to 
correct or supplement my overview.

John Morris

At 3:13 PM -0400 4/9/03, Joseph Reagle wrote:
>I've reviewed [1] as part of my background research for the "Beyond-HTTP"
>P3P taskforce [2]. I'm not presently able to draw any conclusions with
>respect to [2] but I think it's an interesting document and have two
>comments.
>
>[1] http://www.ietf.org/internet-drafts/draft-ietf-geopriv-reqs-03.txt
>[2] http://www.w3.org/P3P/2003/04-beyond-http.html
>
>[[[
>    5.2. The Location Object and Using Protocol
>    ...
>       Location Object (LO): This data contains the Location Information
>          of the Target, and other fields including an identity or
>          pseudonym of the Target, time information, core Privacy Rules,
>          authenticators, etc.  ...
>
>    Nothing is said about the semantics of a missing field.  For
>    instance, a partially filled object MAY be understood implicitly as
>    the request to complete it....
>]]]
>
>Since a LO contains the core Privacy Rules, one should *not* permit the
>absence of the privacy rule syntax to result in ambigous semantic
>interpretation [3].
>
>[3] http://www.w3.org/TR/md-policy-design#_Semantic_Clarity

I agree -- and I think that the working assumption of the geopriv WG 
addresses this point.  I believe there is agreement in the WG that 
the default rule is that location should receive a high level of 
privacy protection in the absence of rules to the contrary.  In other 
words, the protocol will default to "do not disclose" unless a 
Privacy Rule (in the LO or external) would permit disclosure.

But having said that, I cannot locate anywhere where this default 
assumption is clearly articulated in a WG document.  If it is not, we 
need to add it.

>[[[
>   5.5. Privacy Rules
>    ...A full set of Privacy Rules will likely include both rules that have
>    only one possible technical meaning, and rules that will be affected
>    by a locality's prevailing laws and customs.
>]]]
>
>This, and the example, makes it sound as if these were disjoint sets. "You
>may not store my location for more than 2 days" is very clear even if it is
>overridden by other (legal) rules. This paragraph seems to be confusing the
>articulation of a non-ambiguous rule with the an a posteriori
>interpretation of all operative rules that might exceed the knowledge of
>the Rule Maker or Location Recipient beforehand.

I agree that this discussion warrants clarification.  The goal was 
not to suggest two exclusive sets:

	1.  technically unambiguous rules, and
	2.  rules that will be affected by local law, etc.

Instead, the goal was to acknowledge that (a) some rules can be 
expressed in technically unambiguous terms, while (b) other rules 
will not be clear without resort to an applicable legal norm.  But 
both types of rules (a+b) can certainly be affected or overridden by 
a local law.   What we were concerned about was to make clear that 
the set of (b) rules were still valuable to include even if they did 
not have a single unambiguous technical meaning.   But in any event, 
the clarification you suggest is worthwhile.  I'll work on some 
specific language to address the two points raised here.

Let me change gears and give the BH/P3P task force a quick overview of geopriv:

Greatly summarizing the geopriv charter [4], the mission of the WG is 
to create a privacy protecting protocol to be used when location 
information is transmitted.  In the language of the WG, the WG is 
creating a "Location Object" [LO] which will be able to contain both 
location information and privacy rules (or a pointer to external 
privacy rules).  The protocol must be usable in situations with 
constrained devices with low bandwidth and/or computing power.  The 
WG is approaching a final requirements draft [5].

That draft says that the Location Object must be able to carry a 
limited set of privacy rules, and must be able to refer to an 
external set of rules as well.  There is not final agreement on 
precisely what privacy rules will be built into a LO, but the most 
recent proposal of some WG participants (including me) is found at 
[6].  Even a couple of elements in that version, however, are in a 
state of flux (something that I will try to bring back to the geopriv 
list shortly).

Looking more broadly, the WG has NOT decided on the format for the 
expression of the LO, but XML has certainly been discussed as a 
strong candidate.   Even more generally, I think that many in the 
geopriv WG would be open to using, or at least being compatible with, 
P3P, so long as that goal did not slow down geopriv's already slow 
(but significantly accelerating) progress to date.

Let me know if there are more specific points about geopriv that the 
[email-masked] wants to know at this point.....  John

[4]  http://www.ietf.org/html.charters/geopriv-charter.html
[5]  http://www.ietf.org/internet-drafts/draft-ietf-geopriv-reqs-03.txt
[6]  http://www.ietf.org/internet-drafts/draft-morris-geopriv-core-01.txt

---

From: Joseph Reagle <[email-masked]>
Date: Wed, 09 Apr 2003 15:13:02 -0400

[[[

[[[
  5.5. Privacy Rules

---

From: Carl Reed <[email-masked]>
Date: Fri, 25 Apr 2003 14:01:15 -0600

Sorry for the slow delay in responding to this email. Given John's statement

"the WG has NOT decided on the format for the expression of the LO, but XML
has certainly been discussed as a strong candidate.   Even more generally, I
think that many in the geopriv WG would be open to using, or at least being
compatible with, P3P etc"

I would suggest that the group also consider the work of the OpenGIS
consortium in relation to the OpenGIS Geography Markup Language (Version
3.0). GML is a set of XML schemas for encoding (for transport or storage)
geometry (points, lines, ellipses, polygons, splines, etc), metadata about
location, coordinate reference systems, and many other aspects related to
location. GML is being used more and more for the encoding and transport of
location based information across the Internet. Many GIS vendors have
implemented the ability to generate and consume GML. Further, the Open
Mobile Alliance (OMA) has incorporated the coordinate reference system and
geometry schemas into the Mobile Location Platform API. Finally, a number of
OGC members are now implementing the OGC Location Services core set of
interface specifications. These specs use the same geometry and CRS schemas.

Just a thought.

Regards

Carl Reed
OGC

----- Original Message -----
From: John Morris <[email-masked]>
To: Joseph Reagle <[email-masked]>
Cc: <[email-masked]>; <[email-masked]>;
<[email-masked]>; <[email-masked]>;
<[email-masked]>; <[email-masked]>
Sent: Wednesday, April 09, 2003 4:05 PM
Subject: Re: [BH] Comments on draft-ietf-geopriv-reqs-03

---

From: "James M. Polk" <[email-masked]>
Date: Fri, 25 Apr 2003 16:15:30 -0500

>interface specifications. These specs use the same geometry and CRS schemas.

How does one go about gaining access to this/these for Geopriv efforts in 
the (near) future?

>OGC

cheers,
James

            *************************************
        "The road to destruction is well traveled and crowded,
if you choose to get on that road, destruction will hit you head on"

---

From: [email-masked]
Date: Fri, 25 Apr 2003 16:34:24 -0600

Hi James -

All adopted OpenGIS specifications are publicly available and royalty free.
They may be found at www.opengis.org/ogcSpecs.htm . Then go to either
"OpenGIS® Implementation Specifications" or "Access approved schemas" to
actually download a given OpenGIS specification. Look for GML 3 related
links.

Cheers

Carl

----- Original Message -----
From: "James M. Polk" <[email-masked]>
To: "Carl Reed" <[email-masked]>; "John Morris" <[email-masked]>;
"Joseph Reagle" <[email-masked]>
Cc: <[email-masked]>; <[email-masked]>;
<[email-masked]>; <[email-masked]>;
<[email-masked]>; "Ron Lake" <[email-masked]>
Sent: Friday, April 25, 2003 3:15 PM
Subject: Re: [BH] Comments on draft-ietf-geopriv-reqs-03