From Status to Validity

In an earlier post, I wrote about some of the material we didn’t include in our book on the basics of PKI. It was not included because the notion of the “Validation Authority” had yet to evolve out of one of the technologies we did discuss: OCSP. As conceived by VeriSign and Microsoft initially, OCSP was involved with the revocation of certificates and otherwise delivering “status” information.  The key word here was “status”. It can mean almost anything and can specifically mean "validity' – a subjective evaluation at best. And it is in validity that we find a story to tell; one far more interesting than the issues of revocation and compromise of certified public keys! Validity lies at the heart of a mindshare war going on between the Shibboleth and OpenID communities - 2 approaches addressing single signon.

I doubt that book talked much about it (tho I cannot really remember which control topics I wrote about, any more), Validation Authorities aimed to authorize a farm of servers listening on anycast addresses across the internet to make "status" statements on behalf of a leaf CA. The signatures could be across simple small messages (IETF), or Merkle hash trees (patented). Whereas a Validation Authority validation network might use IETF's signed OCSP messages to dynamically issue (a) signed statement(s) about a static cert to which various attributes about the subject (managed by third parties) may be attached, a SAML IDP issues signed XML "assertions"...to which various attributes about the subject (managed by third parties) may be attached (strangely enough). By fiat, attributes can be entitlements, and attribute contracts would (I grudgingly suppose) implement what a CISSP would probably call a network-/federation- wide non-discretionary security policy by controlling their release (IDP side) and acceptance (SP side).

From what I can tell, the thought-leaders of the SAML world are in a battle to the death with the thought-leaders of the OpenID2 protocol world. Both communities focus on single signon for the web, but their models of administration and management of communities could not be further apart. Grass roots OpenID wants you to be in charge of your own critical infrastructure. The Shibboleth group within the SAML world believe in the Trusted Third Party model, where you are merely a subject about which statements are made by others. You never speak for yourself. What matters is those who will act for you, in your security interests.

The Controlling Nature of Metadata

The issue at stake for the warring parties concerns the role of metadata – and its role in enforcing security policies.

Though SAML2 standards have long had an excellent metadata model to ease the setup of websso links, it is optional. It is poorly supported by commercial vendors, and except in the Shibboleth sub-community it is not viewed as security critical. For Shibboleth folk, metadata is the whole world : the means of orchestrating the security of a web-centric  distributed system, controlling the runtimes of many remote computers acting in loosly or tightly coupled meshes, including those formal high-performance computing clusters known as grids. To use terms from networking, its the "control plane" which manages the "data plane". In the core of the Internet, the Shibboleth conception of metadata is the analog of the routing algorithm that controls the convergence of the routing tables in all the reachable cooperating routers – deciding how and if packets are forwarded in a packet switched network. Just as routing protocols communicate metadata about subnets rather than hosts (normally), Shibboleth metadata describes the trustees of security policy: the IDPs and SPs of the SAML2 world (rather than the subject users).

OpenID2 is heavily invested in metadata. Its mandatory and security critical. Without going into much detail, the authority that will speak for you in any given use of the web is nominated by you, and you maintain one or more metadata files containing your "XRDS" instructions reflecting your choice of alternative providers. By your act of pointing to a particular file stored at a URL (or by using XRI name resolution to generate the "XRDS stream" on the fly), the OpenID protocols wrap themselves around your wishes and the wishes of your communicants to create a semi-secure cryptographic channel over which SSO assertions are exchanged. In a Web2.0 world, this is particularly useful as you wander through yet another enrollment for a service, which demands registration details. As you act to bind your openid to this new service provider, you also get to form fill the usual answers to the usual member registration form. Kept at one of your authorities, these attributes flow over the semi secure channel. Now, being only semi-secure and given the access to metadata is so security critical, OpenID standards recommend the use of https channels – thereby availing OpenId of the assurances that https can bring: its SSL handshake, its reliance on PKI ciphersuites, and the warranties and other financial assurances that the better CA deliver to the parties subscribing to their dispute resolution services. This "built-in" governance model for OpenID2 is delivered via the parties subscription to the relying party services of the medium assurance level,  commercial CAs – TTPs that leverage the trust model known as the “freedom to contract” – a leverage that is expected to serve OpenID as well as it evidently served e-commerce in the 1990s.

What Happens to the Metadata known as PKI?

Now, OpenID is indirectly promoting PKI-based trust networks – as an adjunct to its own metadata -- where the PKI built into https brings assurance and governance by the SSL CAs. And that is a problem for those elements of the SAML community that essentially deny PKI has any role to play in those areas. In fact, that which high-end PKI does in this area of assuring and governing asserters and consumers is that which SAML2 metadata management is viewed as more properly doing. And, there is only room for one sheriff in town.

The Shibboleth communities learn-ed view on “go” (signed) metadata and “down with”  PKI can be read at http://xml.coverpages.org/Cantor-SAML-v20-MetadataInteroperabilityProfile-WD01.pdf. For me, what is interesting is not the attack on PKI (which I find timely), but the rationale concerning why Shibboleth metadata can play PKI’s erstwhile role as a framework for trust networking. And there, finally, we get back to validity.

Assertions vs Certifications vs Validity

Any computer scientist learning formal logic learns to distinguish truthful assertions from questions about the validity of theorems linking several true statements into an argument about topic X. Students learn that two models can both be valid at the same time, given some contextual assumptions. Even in core science, high school students learn that what is true at the macro scale and expressible with Newton’s differential formulas from the 17th century is not true at the micro scale, where an entirely different branch of mathematics not only expresses the peculiar laws concerning the world of micro forces … but proves that Newton’s laws do not hold. The Newtonian calculation, even one formally certified as correct by a national observatory,  simply produces the wrong answer given actual obsevations. That is, the notion of limits in conventional calculus does not necessarily extend from the world of macro forces to the world of micro forces, given actual observations by physicists! Yet, both sets of laws are "valid" – in their respective context.

In the world of SSO, validity is more mundane than in physics – but no less interesting. For the very cryptographic keys that secure and assure the actors doing their SSO thing have a lifecycle. They must be generated (ideally in a secure manner, to create a secure initial condition), they must be used, and given their nature they must be revoked - when no longer bound to some person - or they must be quickly flashed to the world as compromised (because someone published the keying secret, or the consequences of the loss of secrecy goes beyond some tolerance for risk taking). But beyond lifecycle, certified public keys also bear value judgments. In particular, the critical element of any PKI – the signed public key – bears the judgment of its issuer, but contemplates that others will also pass meta-judgment during an act of “reliance” on the issuer. That meta-judgment is nothing more that a use of validity, acting as a metric for the user's acceptance of the issuer's original judgment.

When I wrote my PhD dissertation on validation, I tried to argue that third parties should exist to support relying parties accepting certificates issued by CAs. Known as Validation Authorities, they would apply some or other validation model to a certificate, and let the relying party know their opinion. For example, I the Validation Authority consider a public key certificate within 6 months of its expiry date as too risky for your use. I hereby give it a status of “invalid” and recommend you treat it as unreliable (for your purposes). Oh, and Ill use the IETF-standardized OCSP response data structure to communicate this status value to you, signing it even – to express my ”authority”. Since OCSP also involves you sending a request message, I'll even let you specify which validity model you want applied: mine, yours, or that community of interest over there! The more validity models the merrier!

Now, Validity as Control

The problem with the validity thesis concerns its applicability to the control sphere. Once the relying party is applying a validity model other than that of the issuer, the issuer “loses control” -- particularly if another third party is advising the end user. And, that means loss of economic value of the management service being provided by the issuer - to that other third party closer to the user. One quickly arrives at the ludicrous American situation that one can be authoritatively certified as married… but the certificate may be designated invalid depending on who applies which model of validity. You can be both married and not married, at the same time. In one state you need to rent two hotels rooms; in another, only one.

In the Shibboleth community leadership's proposal, there is a triple denial ongoing – which is radical. Not only is the certificate issuer's validity model to be ignored, not only is the third party's validity model to be ignored even if delivered by OCSP and CRLs/CKLs (or ARLs/AKLs), even the relying party's own validity model MUST be ignored. The only model that matters is that of the maintainer of the Shib metadata, as expressed in signed XML. (Note: A private memo I received states that the control characterization of the Shibboleth leadership's proposal - the final MUST clause, in particular - is far too strong.)

From Full Control to Full Distribution

The nice thing for the OpenID world is that this control paradigm is not a threat to its model of metadata, if one thinks liberally. Its an endorsement of OpenID, in fact. Nothing stops anyone assuming the role of being a "maintainer" of SAML2 (signed) metadata - which contrasts with a worldview in which only “the” maintainer (whoever that one entity may be) gets to speak authoritatively on questions of validity. In fact, that is really only what OpenID already does, in allowing me and you to publish any one of n metadata files about ourselves, and direct the SSO protocol to use a particular one.

We can now conclude. OpenID relies on metadata, and Shibboileth leadership folk are proposing the SAML world moves metadata into the same seat of power. The Shibboleth notion of shifting responsibility for expressing the validity model into a metadata "maintainer" is identical with the older Validation Authority model. My own thesis in my abortive PhD dissertation (which I did actually get formally examined by UK academics ...whereupon it recveived a "total utter fail" grade, note very well) recommended that a properly conceived infrastructure for validation would operate at the level of the individual - which aligns nicely with what the OpenID movement finds itself doing in practice and what the Shibboleth team's technical proposal can actually support. Finally, the Shibboleth leadership team's proposal recognizes that the distribution of signed metadata itself depends ultimately on PKI to verify metadata own signature, - which must be then validated using PKI-centric validity constructs. Considering earlier efforts in the same topic area, just as the IETF specified that a CA might sign a cert "authorizing" a Validation Authority to make validity statements using an OCSP responder, so a CA might issue a certificate that authorizes a Shib-styled metadata maintainer to use its certified signing key to digitally sign “SAML2 metadata”.  

* * * *

Postscript. The nice thing about all this world of validity… is that its carefully and properly patented in embodiment-free language, awaiting the market to develop to the point where it calls for the work that Validation Authorities do! As for my PhD dissertation? Oh well, it got a fail! I’m sure it was a well deserved fail, given academic standards for doctoral degrees. If I consider its thesis though (validity, and who can be an authority performing validation) perhaps I should just publish it myself!

"How to apply openid to linked data and semweb agents?" is a harder question to answer than I ever imagined it would be.

Over the last 12 months, I've built up a pretty complete design-history for myself, linking up a rich history of open standards SSO schemes ending at OpenID2. This started with the chained SSO model in 1986-era X.500, through Kerberos-centralist world of the NOS-based network, through distributed PKI-based military messaging a la MISSI/P.772, through RSA's inter-domain cookie issuing by isap/nsapis allow for remote reliance on SecurID tokencodes, to S2ML/SAML push/pull artifacts and websso, to recent Liberty ID-FF profiling for different classes of UAs, to OpenID1 for UCI and OpenID2 for UCI & XRI-based authority resolution environments. This of course just all leads to Henry's own profiling efforts of all that "wealth of stuff" ...for the world of the "linked data".

Since OpenID Auth v2 seems rather weak as it applies to all the various flavors of web services (or comes with rather too much javascript or DOM-centric religion, where it does apply), I've been focusing on SAML2's "ECP view" of the world - as a stepping stone between the web culture for SSO (that is now commodity) and web services SSO culture (that is emerging - in as yet heavyweight models). In parallel, I'm trying to see which bits of Liberty/SAML2 IDP discovery (via common domain cookie services) are actually useful and viable, as they MIGHT apply  to ECP trust-fabric switching. My notion is that once something all works, viably, then one can turn back to OpenID extensions standardization to bring down the bar (and the cost).

In Figure 5 of  http://www.projectliberty.org/liberty/content/download/319/2369/file/draft-liberty-idff-bindings-profiles-1.2-errata-v2.0.pdf, we see a diagram of somewhat similar complexity to your own original diagram of "OpenID2 meets Semweb agents"- to which you later drew contrasts. Of course, the Fig 5 diagram targets a custom UA (not a browser), much like a semweb UA, perhaps.

I don't fully understand the rationales of all the design elements and the messages shown in that diagram; and I don't fully understand which specs control which bits of the ECP profile's protocol stack (SAML2 contributes a bit, as does the Liberty-controlled PAOS spec, as does Liberty ID-FF - apparently). But I _have_ made some practical progress - trying to see if ECP technology from open sources is approaching commodity status - such that the likes of me ...with low-end programming skills ...can now also participate, _finally_.

On that practical path, I do now "amended" the open source Shib2 SP server src, so it essentially does steps 1 - 3, using a developer UA. And, I built Peter Pritchard's openliberty ECP plugin for Firefox - which, placed in a browser container, would do the "signal handling" assumed in the space between steps 3 and 4. With a bit more effort or help, I may even get it to work and actually talk to the Shib2 SP-side SAML server. But I'm already worried, since it brings alot of Mozilla-relegion and implementation-centric baggage.

Once all that works once, however,  I'm likely to abandon the effort to actually apply the openliberty client - since it focuses on browser-based, user-centered UI for Selecting IDPs, in a "lets-go-compete" with cardspace and JanRain's idselector.com mission). Rather, I may to back to applying my own data-centric/metadata-aware UA as the ECP agent, which is similar to your semweb user agent I suspect. And there, "trustworthy" metadata will guide the switching path chosen through the SP->IDP trust fabric, rather than users. Now, I have various patented techniques and other IP I can (privately) call on to accomplish automatic, trust-metric-based switching in an XRI-style tree walking environment, and you of course have the alternative W3C:WOT and PGP traditions to call on - addressing the FOAF tradition. Once the overall flow is right using a variety of modern, trust fabric infrastructures, perhaps the trick will be to then cast it all in terms of simple, OpenID extensions.

_________________________
Peter Williams

_______________________________________________
general mailing list
general@openid.net
http://openid.net/mailman/listinfo/general

Looking for what SAML2 and OpenID2 each do best, and where they act in common with regard to security handling rules for their respective "Authentication Request protocols", I noted the following in [1]

"Note that if the <AuthnRequest> is not authenticated and/or integrity protected, the information in it MUST NOT be trusted except as advisory. Whether the request is signed or not, the identity provider MUST ensure that any <AssertionConsumerServiceURL> or <AssertionConsumerServiceIndex> elements in the request are verified as belonging to the service provider to whom the response will be sent. Failure to do so can result in a man-in-the-middle attack."

First, saml and OpenID are similar in that both characterize the fundamental controls in their handshake design in terms of "requests" (not responses).

Second, in the SAML case, metadata may be signed or not signed; and, requests be signed or not signed, similarly. As we see above, "verification" is obligatatory for the unsigned-request/unsigned-metadata cases. If I replace the term verification with the term "OP/RP discovery", we have a situation much like in OpenID2, mapping identifiers/realms into endpoints.

I'm wondering which infrastructure to use to distribute my SAML metadata (and possibly a Realtor's public FOAF data). One option is to put it in our application repository (RETS - an RDF like SPARQL server, that has a GETmetadata URI-bound transaction and that permits "community-extensions" to the (RETS) metadata schema). Another option is to put it in the XRDS/XRD, so XRI resolution can be shared when securing flows between SAML2 endpoints and also between OpenID endpoints. (I could even extend the RETS transaction model privately, to deliver XRDS documents!) Now, if I go with XRI as the data model, would I define an extension for the XRD schema, importing the SAML2 metadata schema say? If I do that, can this legitimately be done by private entities in the management model, or is this right reserved for an OASIS process?

The elements in the XRD schema are intended for generic resource description, including the metadata necessary for XRI resolution. [2]

An XRDS document is intended to serve exclusively as an XML container document for XML schemas from other XML namespaces. Therefore it has only a single root element xrds:XRDS in its own XML namespace identified by the XRI xri://$xrds. [2]

It also has a single attribute, xrds:XRDS/@xrds:ref of type anyURI that identifies the resource described by the XRDS document. The formal XML schema definition of an XRDS document is provided in Appendix A. [2]

[1] http://www.oasis-open.org/committees/download.php/22389/sstc-saml-profiles-errata-2.0-wd-05-diff.pdf

[2] http://www.oasis-open.org/committees/download.php/17293

_________________________
Peter Williams

Work in Progress.

Topic

In Tying FOAF identity with the identity semantics of OpenID - v2.7 we discussed how the conceptual model of FOAF could augment the notions of identity present in OpenID Auth 2.0. We extend that discussion in this memo by addressing the question: Can we apply SPARQL, FOAF and WOT to assure the asymmetric keys used to strongly authenticate an OP Identity? We propose a solution to several problems that we view as characterizing the current lack of strong authentication in OpenID protocols. We outline a study of how each solution element addresses a need in a Realty application of OpenID, and state why the solution to each problem is a proper security requirement for any realty infrastructure adoption OpenID.

Background Material

[For each core technology, provide a precis of the major components. Bias the presentation towards the elements that we will actually leverage]

OpenID

SemWeb

FOAF

WOT

SPARQL

Introductory Ideas

[State the main problem - OpenID lacks strong authentication. There is insufficient protocol to gauge assurance, in general.]

State subproblem #1:  Staying close to web means use HTML discovery, applying delegation. How do we propose putting an encoded SPARQL query into the delegation field?

State subproblem #2:  FOAF provides a method for reasoning with user-centric trust lists (knows: relations). How do we propose applying knows relations to assure the strong authentication of OpenID consumers to OpenID Providers ?

State subproblem #3: OpenID Consumers and OpenID Providers are mutually suspicious. How do allow one SPARQL query from the user's delegation value to be applied by both the Consumer and the Provider?

State subproblem #4:  FOAF is not a standard part of OpenID Auth 2.0. How do we propose using namespace extensions to indicate the desire for SPARQL processing of FOAF files?

State subproblem #5:  OpenID extensions indicate the claims the Consumer wishes to receive. How do we propose using using SPARQL and FOAF to satisfy the requested claim set and perform claim transformation?

State subproblem #6:  FOAF normally contains public data. How do we apply AX, namespace extensions , SPARQL and additional FOAF classes to enforce access controls for a variety of policies?

Elements of Strong Authentication

[Outline the proposed solution components]

States

Messages

Processing

Impact of Strong Authentication on Realty Infrastructure

Comments solicited in any inappropriateness on the material that follows - which attempts to organize how I will (hopefully) participate on an DIDW panel discussion touching on OpenID topics, Monday at 2:30.

I will amend my project description to 6 minutes. (There are 3 _optional_ picture slides to go with it.). It will highlight how 15k San Francisco Realtors all got (SAML2) SSO in February of this very year - which seems appropriate case study --  since San Francisco is our host city. This is all very concrete. If its helpful, Id be happy to go first and help warm up a cold audience.

To tune that story for an open panel forum, the last 2 minutes will be on the topic of how consumers and realtors might interact using web2.0. This will introduce how we are thinking of using OpenID on the so called "client portal" - a per-Realtor hosted collaboration site where potential homeowners work with the realtor one on one -  to find the right homes for their tastes. Either we can require homeowners to go get a Microsoft passport/hotmail/LiveID account to logon to the portal , which means we must rely on WS-Federation SSO from LiveID, or they do the same with an OpenID Provider - where we relying on OpenID SSO from the likes of Vidoop. Which would be better, given these 2 federation options could equally apply to any one of potentially 2 million people in N California who will interact with a Realtor, in the next Year? Which option could we actually see becoming a reality in a 3 month timeframe?

The opening piece would leave open the question: Why ...would one take longer than the other to make happen? Does this therefore bias the selection of SSO technology?

updates

Ok. I have 15 minute talk for you on Quattro - an actual, live deployment of WebSSO that occurred in the last 9 months - for almost 100k Realtors across N California, operating out of about 5000 brokerage offices where the state licensing regulations are enforced. I will describe why the connecting parties opted to use websso to enable all realtors to access all sources of property listing data in all 9 counties. The economic facts tell a fascinating story (monthly fees per realtor went down in most cases, the security program paid for itself, no user resentment was detected despite issuing one-time-password security tokens as the same time.)

If I can get authority to discuss certain matters that reflect backroom concerns, I will publicly state why these parties opted to address certain regionalization trends going on in N California market with this "federated" approach, rather than use alternative schemes. Additionally I can summarize the impact in general terms: who won out and who lost out by this combination of business/technology tactics.

Parallels with equivalent rollout programs on the E coast can be stated, with some discussion of how the scheme uses websso services to solve mostly state-level problems while also addressing national-scoped websso problems. For example, whilst locally focused, any one of 1.3M realtors will also need from their local portal site to get SSO access a certain service provider vendor (in CA, perhaps), who happen to operate nationally-syndicated services related to backroom management (workflow, records management, compliance,...).

This can finish by stating how critical it was that there existed a mature technology standard, a multi-vendor climate, commodity security and pricing structures, and ...proof that other industries were moving in the same direction so that the Realtor will one day have within their webSSO network access to the (mortgage banking brokers, title insurers, fiduciary escrow agents, county recorder) offices - all of which are of course necessary to close the conveyance of your real property.

As almost everyone in the room will have personally touched this process, as a buyer/seller, it usually easy to put yourself in the shoes of the Realtor and see just why such folk need such networking capabilities - to get your transaction closed by 1pm and recorded, during the window when the loan is both funded and the recorder's office is open.

 

From: Story Henry [mailto:henry.story@bblfish.net]

Sent: Fri 9/21/2007 3:12 AM

To: Peter Williams

Cc: OpenID General

Subject: Re: [OpenID] cryptographics web of trust

On 15 Sep 2007, at 05:16, Peter Williams wrote:

> I played more with your foaf file, its wot, its implied recommendation

> to certain public keys.

> 

> http://yorkporc.spaces.live.com/blog/cns!5061D4609325B60!167.entry

By the way, one thing to remember about writing blogs is that people may be arriving at your blog from anywhere. So they don't have context. It is important therefore to decontextualise as far as possible what you are writing.

The query in the original reference used a java-script-like server-side scripting language, extended with a proprietary RDF query language. Its easy to learn, as its very similar to that underlying a million older Microsoft websites using Active Server Pages (ASP). A lot of programmers would relate to it (if indeed I contextualized, properly in an ezine-grade blogsite, seeking recommendations).

What matters most for now is the query design, not the language of its expression. Perhaps, continued discussion should aim to help OpenID community (a) focus on the appropriateness of its end-used identifier rules (https/http/no-fragments), (b) review how proposed wot:SigEvents documenting KeySign-ings may support OpenID Auth by adding assurance to the distribution of keying material, (c) allow optional FOAF discovery to add assurance to OpenID HTML Discovery of URIs, (d) let FOAF optionally be used as a basis of fulfilling AX queries, (e) let FOAF be a source of security policy controlling the release of attributes via AX, and (f) let FOAF/RDF document and/or define OpenID namespaces and protocol extensions.

In that vein, I can then note that FOAF cards are one of the earliest of SemWeb experiments - one that "captures its major design tenets". (I don't want to "abuse" SemWeb, as some claim SOAP abuses the "intended role" of XML.) I note that FOAF vocabulary is used most of the examples in the SPARQL Query Recommendation. I note than foaf:openid is now an experimental term. I note that versions of FOAF's own ontology have been signed using the WOT vocabulary. I note how your own FOAF card shows how one might similarly sign some byte form of a unique PersonalProfileDocument, bearing your openid assertions and a list of URI references to various friend assertions. I note that some of those friends have openids and publickeys. I note you have certified some of the openid/cardURI/pubkey bindings, essentially.

So lets perform another thought experiment - with just those elements.

Rather than experiment further with that javascript language, lets only use the SPARQL use case models shown in and around http://www.w3.org/TR/rdf-sparql-query/#specDataset .

Lets say henry's new friends include:-

<http://example.org/foaf/aliceFoaf>

<http://example.org/foaf/bobFoaf>

Can we imagine that each graph indicated the n FROM NAMED elements in the query is one of the URLs henry's card file points out - each pointing to the card of each of henry's friends?

PREFIX foaf: http://xmlns.com/foaf/0.1/

SELECT ?src ?friendopenid ?friendpka
FROM NAMED http://example.org/foaf/aliceFoaf
FROM NAMED http://example.org/foaf/bobFoaf
WHERE
{
    GRAPH ?src 
        {
          ?x wot:pubKeyAddress ?friendpka .
          ?x foaf:openid ?friendopenid
        }
}

Can we now imagine that henry's card also has a "foaf:queryme" term. Its value might the conventions of the SPARQL protocol binding for HTTP URL. The query above would presumably be encoded as the queryme object, citing a relative-URL to be resolved against the locally-scoped name #me

[ foaf:queryme #me?query=PREFIX+foaf%3a+%3chttp%3a%2f%2fxmlns.com%2ffoaf%2f0.1%2f%3e%0d%0aSELECT+%3fsrc+%3ffriendopenid+%3ffriendpka%0d%0aFROM+NAMED+%3chttp%3a%2f%2fexample.org%2ffoaf%2faliceFoaf%3e%0d%0aFROM+NAMED+%3chttp%3a%2f%2fexample.org%2ffoaf%2fbobFoaf%3e%0d%0aWHERE%0d%0a++%7b%0d%0a++++GRAPH+%3fsrc%0d%0a++++%7b+%3fx+wot%3apubKeyAddress+%3ffriendpka+.%0d%0a++++++%3fx+foaf%3aopenid+%3ffriendopenid%0d%0a++++%7d%0d%0a++%7d . ]

Can we imagine that an address book tool used to maintain Henry's friend list also rewrites the foaf:queryme?

Can we imagine the query might reference an inference rulebase, that allows the query to prefer to pickup henry's copy/endorsement of Alice's pubkey from henry's website (rather rather than the copy from Alice's own website?)

Is there an existing "standard" SPARQL query that takes a PersonalProfileDocument card, and reduces the list of knows relations to a set of named graphs in a "template" SPARQL query - one that gets specialized by some kind of internal GRAPH "join" to then lookup the friends' current openids, or pubkeys, or other "X" terms that a particular FOAF applications focuses on?

Just a few ideas, to play with.

From: 
Peter Williams

Sent:
Thu 9/20/2007 12:18 PM

To:  

Cc: 
foaf-dev

Subject: 
FOAF, property listings, updating shows relations, subProperty (pun) searches, federate data, friend datameshes, openid CCA

Attachments:

N3 Analysis

If we store the stream as a file on my computer's Desktop file folder, rather than explore the rdf+xml media used as a wire-transfer syntax for the RDF model, we can explore it more usefully using the highly readable N3 notation.

@prefix desktop: <file://C:/Users/pwilliams/Desktop/>.
@prefix peter: <file://C:/Users/pwilliams/Desktop/foaf.rdf#>.
@prefix ns10: <http://>.
@prefix ns11: <http://bblfish.net/>.
@prefix ns12: <http://bblfish.net/blog/>.
@prefix ns4: <http://bblfish.net/people/henry/card#>.
@prefix ns13: <http://blogs.sun.com/bblfish/>.
@prefix ns14: <http://del.icio.us/>.
@prefix dcterms: <http://purl.org/dc/terms/>.
@prefix rel: <http://purl.org/vocab/relationship/>.
@prefix admin: <http://webns.net/mvcb/>.
@prefix ns9: <http://www.ldodds.com/foaf/>.
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>.
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
@prefix owl: <http://www.w3.org/2002/07/owl#>.
@prefix foaf: <http://xmlns.com/foaf/0.1/>.

desktop:foaf.rdf a foaf:PersonalProfileDocument;
    dcterms:modified "2007-08-28T05:59:11Z";
    admin:errorReportsTo <mailto:leigh@ldodds.com>;
    admin:generatorAgent ns9:foaf-a-matic;
    foaf:maker peter:me;
    foaf:primaryTopic peter:me.

<file://C:/Users/pwilliams/Desktop/foaf.rdf#> owl:imports
    <http://xmlns.com/foaf/0.1/>, <file://C:/Users/pwilliams/Desktop/>,
    <http://purl.org/dc/terms/>, <http://purl.org/vocab/relationship/>,
    <http://webns.net/mvcb/>, <file://C:/Users/pwilliams/Desktop/foaf.rdf#>.

peter:me a foaf:Person;
    rel:acquaintanceOf [ a foaf:Person;
                                     rdfs:seeAlso <http://bblfish.net/people/henry/card#>;
                                     foaf:aimChatID "unbabelfish";
                                     foaf:homepage <http://bblfish.net/>;
                                     foaf:mbox <mailto:henry.story@bblfish.net>,<mailto:henry.story@gmail.com>, <mailto:henry.story@sun.com>;
                                     foaf:name "Henry J. Story"; foaf:nick "bblfish";
                                     foaf:weblog <http://bblfish.net/blog/>, <http://blogs.sun.com/bblfish/>, ns14:bblfish
                                ];
    foaf:family_name "Williams"; 
    foaf:givenname "Peter";
    foaf:mbox <mailto:pwilliams@rapattoni.com>;
    foaf:name "Peter Williams";
    foaf:nick "pe";
    foaf:openid <http://openid.sun.com/peter>;
    foaf:title "Mr";
    foaf:workplaceHomepage ns10:www.rapattoni.com.

A number of interesting identity "deep" semantics of the FOAF file become apparent. They appear to take into consideration the location of the file and the just who is doing the (possibly self) documentation.

In the statements given above, we see that the FOAF file knows itself to be located at a file: URI reference, showing how this documentation makes FOAF no longer quite so http-centric. Clearly, in the general case the space of identity semantics must go beyond the HTTP Protocol, and http-specific security schemes such as https. For example, if we look at ns10:www.rapattoni.com one sees from @prefix ns10: <http://>. that the "http" URI scheme is just another namespace.

From the fact we as readers now know that the RDF statements refer to a document tied to a particular location, we also know that it is a third party issuing this document. The FOAF file is a historical document set at a point in time and at a particular location, rather than an active document being made here and issued as a set of assertions.

This FOAF file contrasts with self-documenting FOAF statements that are assertions (such as that in the resource representing Henry Story's card). As the nature of such assertions requires the notion of realtime references, we can only refer to them via an act of linking, here. To display them in this post would be to convert the assertion that Henry's agent makes here and now into a mere document, made in the past.

This post updates "Tying FOAF identity with the identity semantics of OpenID".

Draft 2.7 addresses core organizational issues, most stylistic comments, uses correct RDF terminology and relationships,  and has removed large pictures (which Live Spaces decided to sample to save file space). Typo removal is ongoing. Phrasing polishing continues. RDF+XML in Appendices has been augmented with N3 notation.

Introduction

One of the features of OpenID Auth 2.0 is its reliance on discovery schemes to validate identity. One of the features of FOAF is its reliance on the RDF's formalism of the notions of identity, assertions (of identity) and claims (about identity). In this article we discuss how these 2 features might be combined to harmonize the intuitive notion of identity used in OpenID with the formalized concept of identity used in FOAF.

The aim of our discussion is put OpenID Auth 2.0 on a more solid formal footing -- one that is grounded in RDF Semantics. Once formalized, the security properties of OpenID Auth protocol will be amenable to formal, reasoning-based security analysis. As a valuable side-effect, we would hope to characterize how what we call a "FOAF-aware" Relying Party Agent may exploit a FOAF file during discovery.

Simplifying Assumptions

Identity

Though the end user typing a "User-Supplied Identifier" into a website's login page may be either a URI or an XRI, we simplify the discussion by eliminating the case of the user supplying an XRI -- unless it takes the form of an HXRI (see wiki). To further simplify, we eliminate the need for considering normalization by requiring the user to supply an Absolute URI. We shall assume that simple form-filling browser modules will populate OpenID login fields, automatically.

An absolute URI contains the name of the scheme being used (<scheme>) followed by a colon (":") and then a string (the <scheme-specific- part>) whose interpretation depends on the scheme. [See section 3, URI]

Discovery

OpenID Auth 2.0 defines several discovery methods involving what the authors' refer to as an "Identifier". This URI reference is used to discover "identity" (amongst other names such as the OpenID Provider Agent endpoint, and the "OP Identifier" name of the Agent itself).

Discovery is the process where the Relying Party uses the Identifier to look up ("discover") the necessary information for initiating requests.[OpenID Auth 2.0]

We concern ourselves only with the first method: HTML-based discovery. By imposing this restriction we stay close to the web. Staying close to the web will allow us to more consistently apply the notions of identity that FOAF inherits from RDF.  Thus, we opt to eliminate those methods of discovery that rely on XML documents that are not a concrete representation of RDF resources, such as XRDS documents (see YADIS Protocol). Discovery shall involve only relying on the HTTP protocol, HTML documents and resources denoted by an RDF document.

Defining a Test for "Assurance" of Identity

While performing the OpenID Auth 2.0 protocol, we will require a Relying Party Agent that is "FOAF-aware" to "validate"  -- via "FOAF-enhanced HTML-based discovery" -- that the Absolute URI supplied by an end user must be a person's legitimately-asserted OpenID.  This validation is characterized as a "test" that there are adequate "assurances" that the identity assertions and associated claims are true, before OpenID Auth 2.0  attempts to perform its basic service of authenticating the user citing the identity  -- using passwords, smartcards, biometrics, etc.

We define two tests of legitimacy. The test of "Basic legitimacy" is determined by confirming that the openid Property is present in the instance of Person class of an authentic FOAF file that contains a single PersonalProfileDocument. The test for "WOT legitimacy" is similar, but confirms that the same PersonalProfileDocument asserts an authentic public-key based identity of the FOAF file's author.

Having determined Basic legitimacy, a FOAF-aware Relying Party Agent need not determine WOT legitimacy. The Agent will normally opt to determine WOT legitimacy only when (i) there is no "foaf:openid" property, or (ii) when specifically seeking to rely on WOT-based assurances to the exclusion of other assurances. In contrast to WOT-based assurances, Basic legitimacy derives its assurances from either the security of the Association obtained when using the openid Property in OpenID Auth 2.0 or when using the Record Layer of the SSL protocol leveraged in some OpenID Auth 2.0 exchanges. 

Using Existing Ontologies to Characterize Legitimacy

1. FOAF Ontology: "Inverse Functional" & Basic Legitimacy

In an article posted to the foaf-dev discussion group, the author proposes adding a "foaf:openid" Property to the FOAF vocabulary and explains its objectives:

The foaf:openid property is "inverse functional", meaning that anything that is the foaf:openid of something, is the foaf:openid of no more than one thing. FOAF is agnostic as to whether there are (according to the relevant OpenID specifications) OpenID URIs that are equally associated with multiple Agents. FOAF offers sub-classes of Agent, ie. foaf:Organization and foaf:Group, that allow for such scenarios to be consistent with the notion that any foaf:openid is the foaf:openid of just one foaf:Agent. [article]

It is the "inverse functional" nature of the definition that particularly interests us. That a given Agent may refer to itself using multiple OpenIDs (and that the vocabulary is designed for this scenario) is currently of secondary interest. The inverse functional property of any one of these OpenIDs is what is most important and its nature confirms what the author describes as its potential to address the much wider problem of trust management:

In this way, FOAF and OpenID complement each other; neither provides a stand-alone approach to online "trust", but combined they can address interesting parts of this larger problem space. [article]

OWL discusses the meaning of an InverseFunctionalProperty in highly abstract way:

4.3.2 owl:InverseFunctionalProperty If a property is declared to be inverse-functional, then the object of a property statement uniquely determines the subject (some individual). More formally, if we state that P is an owl:InverseFunctionalProperty, then this asserts that a value y can only be the value of P for a single instance x, i.e. there cannot be two distinct instances x1 and x2 such that both pairs (x1,y) and (x2,y) are instances of P. [OWL]

This abstract definition does not explain how the uniqueness property of the relation is actually maintained. Though clearly needing refinement in a domain-specific vocabulary addressing the missing assurances, the specification already clearly helps formalize the objective of distinguishing a particular Person (or more generally any subclass of Agent) declared in a PersonalProfileDocument located at a particular URL by the assertion of an openid Property.

2. WOT Ontology: "Key Signing" & WOT Legitimacy

The author of a proposed web of trust ontology describes the problem that neither RDF nor RDF Semantics solves the problem of determining who is making RDF statements, such as the foaf:openid statement discussed above.

RDF documents can make any number of statements. Without some kind of signature or other similar verification mechanism, there is no way to understand who made these statements. One way to document who made a set of statements is via the use of Digital Signatures: signing a document using Public Key Cryptography. The WOT, or Web Of Trust, schema is designed to facilitate the use of Public Key Cryptography tools such as PGP or GPG to sign RDF documents and document these signatures.[WOT ontology]

Two terms stand out: "identity" and "User". As the following table shows, identity is a Property, whereas User is a class.

Property: wot:identity Identity - A property linking a public key to the user of the key. Status: testing Domain: wot:PubKey Range: wot:User A term identifying the wot:User of a wot:PubKey - the inverse of wot:hasKey. Useful for providing identifying information about the owner of a Key.

Class: wot:User Key User - A user (agent, person, group or organization) of a PGP/GPG public key. Status: stable in-range-of: wot:identity in-domain-of: wot:hasKey No detailed documentation for this term.

In the context of the WOT, identity is a relationship notion that is tied to public keys and the user of the associated public key pair - known normally as the "owner". What is critical about the definition is its use of a linking (as in "binding") concept between a public key and some owning user.

The term for user contrasts with that for identity. It conceives a non-naming notion of user. It seems to attempt to capture the usage and utility of a public key, once placed in the hands of an end-user. The User markup is not itself a name and is not an identifier of a user - that role is reserved for the identity term discussed above. Rather, user is a bag of user/usage related facts, bearing some relationship to a public key.

The distinctions being drawn can be seen using an example, shown in the figure below (an amended excerpt from the WOT vocabulary). Here, the public key has been signed as represented by a key signing event statement. The concept of the key owner is conveyed by citing properties of the User/usage of the public key - rather than by introducing a URI reference for that user. In this case, expressed as user properties the identity of the public key takes the arbitrary form of two distinguished properties : a foaf:name and a foaf:mbox. Presumably, a domain-specific vocabulary will further refine User.

<?xml version="1.0" encoding="UTF-8"?>
<PubKey rdf:nodeID="KeyA">
    <hex_id>3756EA0B</hex_id>
    <length>1024</length>
    <fingerprint>04FFF3AC57DF217C6D383DBC0110FB923756EA0B</fingerprint>
    <pubkeyAddress rdf:resource="http://foaf.dk/key.asc"/>
    <identity>
         <User>
               <foaf:name>Web Service (foaf.dk)</foaf:name>
               <foaf:mbox_sha1sum>a714a83db77c6ce85211beb56599adf2c4eaa62f
                </foaf:mbox_sha1sum>
         </User>
    </identity>
    <signed>
        <SigEvent>
              <signer rdf:nodeID="KeyB"/>
              <sigdate>2004-02-18</sigdate>
        </SigEvent>
    </signed>
</PubKey>

Asymmetric Keys as Unique Identifiers

Though above we focused on identity and user statements, the example also documents a SigEvent - the RDF statement documenting a realworld act of counter-signing a public key. As shown below, this class is an involved element of the WOT ontology :

A signed public key is of course fundamental to the theory of PKI as used in when binding HTTP Protocol to SSL to form https. Prevailing theory on PKI teaches that the assurance of secure communications protocols inevitably relies on a more basic assurance - produced by some identity protocol that addresses the uniqueness of public keys and their "authoritative" binding to a given User. Prevailing wisdom holds that once bound to the name(s) of an owner user who uniquely controls the private key, a signed public key is regarded as a "certified key" (or "Certificate"). The certificate has all required properties necessary for assuring inverse functional properties, such as those attached to foaf:openid (see above).

An interesting question then arises. If a certified public key has a foaf:openid in its User relation, does testing for the authenticity of the certificate becomes the assurance required to test for the WOT legitimacy of that OpenID?

A Protocol for testing WOT Legitimacy?

Testing for WOT legitimacy may be able to build upon the procedures for testing Basic legitimacy. As shown below, SPARQL queries can be used as a request/response protocol. (These queries were crafted by Henry Story, referring originally to an emulation of the SAML Attribute Request/Response protocol.)

Conclusions and Further Study

No conclusions have yet been drawn, in what is a "study in progress".

Appendix A

In the course of researching the issues underlying this post, we considered actual FOAF files live in the wild. In this first appendix, we look at a FOAF file produced by the foaf-a-matic web-service.

We requested and obtained a FOAF file as described below:-

GET http://gkt09w.bay.livefilestore.com/y1pmOlfD-enEo3DFPaTyVPMHffJ_xgq_aF9xOxx5VBU8yARDbhL0lusFImbriUIc35pM7UoMdWwnDcCKdhiP9qOIA/foaf.rdf

HTTP/1.0 200 OK
Content-Disposition: attachment; filename="foaf.rdf"
Content-Type: application/octet-stream

<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF xmlns:admin="http://webns.net/mvcb/" xmlns:foaf="http://xmlns.com/foaf/0.1/" xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
  <foaf:PersonalProfileDocument rdf:about="">
    <foaf:maker rdf:resource="#me"/>
    <foaf:primaryTopic rdf:resource="#me"/>
    <admin:generatorAgent rdf:resource="http://www.ldodds.com/foaf/foaf-a-matic"/>
    <admin:errorReportsTo rdf:resource="mailto:leigh@ldodds.com"/>
    <dcterms:modified xmlns:dcterms=http://purl.org/dc/terms/
                      xmlns:rel="http://purl.org/vocab/relationship/">2007-08-28T05:59:11Z</dcterms:modified>
  </foaf:PersonalProfileDocument>
  <foaf:Person rdf:ID="me">
    <foaf:name>Peter Williams</foaf:name>
    <foaf:title>Mr</foaf:title>
    <foaf:openid>http://openid.sun.com/peter</foaf:openid>
    <foaf:givenname>Peter</foaf:givenname>
    <foaf:family_name>Williams</foaf:family_name>
    <foaf:nick>pe</foaf:nick>
    <foaf:mbox rdf:resource="mailto:pwilliams@rapattoni.com"/>
    <foaf:workplaceHomepage rdf:resource="http://www.rapattoni.com"/>
    <rel:acquaintanceOf xmlns:dcterms=http://purl.org/dc/terms/
                        xmlns:rel="http://purl.org/vocab/relationship/">
      <foaf:Person>
        <foaf:nick>bblfish</foaf:nick>
        <foaf:name>Henry J. Story</foaf:name>
        <foaf:aimChatID>unbabelfish</foaf:aimChatID>
        <foaf:homepage rdf:resource="http://bblfish.net/"/>
        <foaf:mbox rdf:resource="mailto:henry.story@bblfish.net"/>
        <foaf:mbox rdf:resource="mailto:henry.story@gmail.com"/>
        <foaf:mbox rdf:resource="mailto:henry.story@sun.com"/>
        <foaf:weblog rdf:resource="http://bblfish.net/blog/"/>
        <foaf:weblog rdf:resource="http://blogs.sun.com/bblfish/"/>
        <foaf:weblog rdf:resource="http://del.icio.us/bblfish"/>
        <rdfs:seeAlso rdf:resource="http://bblfish.net/people/henry/card#"/>
      </foaf:Person>
    </rel:acquaintanceOf>
  </foaf:Person>
</rdf:RDF>

The FOAF file has a PersonalProfileDocument element. The rdf:about attribute value ("") ties the document to the URL from which the document is retrieved via the HTTP protocol. It is thus describing itself, assuming one can believe HTTP when it indicates the URL from where it recovered the web page. To address doubts, one can determine the authenticity of the FOAF file by infering that one "relies on" the properties of either (i) the https security mode of the HTTP protocol or, (ii) other means such as a WOT assurance Property.

The document also contains a single Person class instance. The rdf:ID of the Person corresponds to the foaf:maker Property of the PersonalProfileDocument.

The Person resource has an openid Property whose value is unrelated to the URL from which the document may be retrieved. However, by the inverse functional definition of this property, the value is very specifically related to the document itself

The openid Property value is of course an arbitrary URI: http://openid.sun.com/peter. As I am the author of the file, I control the content of the FOAF file and I am able to edit the file to have any value I choose for my openid. I may also store the FOAF file at any URL. These facts contrast with the next FOAF file show in the following appendix.

N3 Analysis

If we store the stream as a file on my computer's Desktop file folder, rather than explore the rdf+xml media used as a wire-transfer syntax for the RDF model, we can explore it more usefully using the highly readable N3 notation.

@prefix desktop: <file://C:/Users/pwilliams/Desktop/>.
@prefix peter: <file://C:/Users/pwilliams/Desktop/foaf.rdf#>.
@prefix ns10: <http://>.
@prefix ns11: <http://bblfish.net/>.
@prefix ns12: <http://bblfish.net/blog/>.
@prefix ns4: <http://bblfish.net/people/henry/card#>.
@prefix ns13: <http://blogs.sun.com/bblfish/>.
@prefix ns14: <http://del.icio.us/>.
@prefix dcterms: <http://purl.org/dc/terms/>.
@prefix rel: <http://purl.org/vocab/relationship/>.
@prefix admin: <http://webns.net/mvcb/>.
@prefix ns9: <http://www.ldodds.com/foaf/>.
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>.
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
@prefix owl: <http://www.w3.org/2002/07/owl#>.
@prefix foaf: <http://xmlns.com/foaf/0.1/>.

desktop:foaf.rdf a foaf:PersonalProfileDocument;
    dcterms:modified "2007-08-28T05:59:11Z";
    admin:errorReportsTo <mailto:leigh@ldodds.com>;
    admin:generatorAgent ns9:foaf-a-matic;
    foaf:maker peter:me;
    foaf:primaryTopic peter:me.

<file://C:/Users/pwilliams/Desktop/foaf.rdf#> owl:imports
    <http://xmlns.com/foaf/0.1/>, <file://C:/Users/pwilliams/Desktop/>,
    <http://purl.org/dc/terms/>, <http://purl.org/vocab/relationship/>,
    <http://webns.net/mvcb/>, <file://C:/Users/pwilliams/Desktop/foaf.rdf#>.

peter:me a foaf:Person;
    rel:acquaintanceOf [ a foaf:Person;
                           rdfs:seeAlso <http://bblfish.net/people/henry/card#>;
                           foaf:aimChatID "unbabelfish";
                           foaf:homepage <http://bblfish.net/>;
                           foaf:mbox <mailto:henry.story@bblfish.net>,
                                     <mailto:henry.story@gmail.com>, <mailto:henry.story@sun.com>;
                           foaf:name "Henry J. Story";
                           foaf:nick "bblfish";
                           foaf:weblog <http://bblfish.net/blog/>, <http://blogs.sun.com/bblfish/>, ns14:bblfish
                       ];

    foaf:family_name "Williams";
    foaf:givenname "Peter";
    foaf:mbox <mailto:pwilliams@rapattoni.com>;
    foaf:name "Peter Williams";
    foaf:nick "pe";
    foaf:openid <http://openid.sun.com/peter>;
    foaf:title "Mr";
    foaf:workplaceHomepage ns10:www.rapattoni.com.

A number of interesting identity "deep" semantics of the FOAF file become apparent. They appear to take into consideration the location of the file and the just who is doing the (possibly self) documentation.

In the statements given above, we see that the FOAF file knows itself to be located at a "file://" URI reference, showing how this documentation makes FOAF no longer quite so http-centric. Clearly, in the general case the space of identity semantics must go beyond the HTTP Protocol, and http-specific security schemes such as https. For example, if we look at "ns10:www.rapattoni.com" one sees from "@prefix ns10: <http://>." that the "http" URI scheme is just another namespace.

From the fact we as readers now know that the RDF statements refer to a document tied to a particular location, we also know that it is a third party issuing this document. The FOAF file is a historical document set at a point in time and at a particular location, rather than an active document being made here and issued as a set of assertions.

This FOAF file contrasts with self-documenting FOAF statements that are assertions (such as that in the resource representing Henry Story's card). As the nature of such assertions requires the notion of realtime references, we can only refer to them via an act of linking, here. To display them in this post would be to convert the assertion that Henry's agent makes here and now into a mere document, made in the past.

Appendix B

We requested and obtained a FOAF file generated by LiveJournal (an OpenID-enabled website), for which the PersonalProfileDocument element is absent.

GET http://homepw.livejournal.com/data/foaf.rdf

HTTP/1.0 200 OK
Content-Type: application/rdf+xml; charset=utf-8

<?xml version='1.0'?>
<!--  If you are running a bot please visit this policy page outlining rules you must respect. http://www.livejournal.com/bots/  -->
<rdf:RDF
   xml:lang="en"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
   xmlns:foaf="http://xmlns.com/foaf/0.1/"
   xmlns:ya="http://blogs.yandex.ru/schema/foaf/"
   xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#"
   xmlns:dc="http://purl.org/dc/elements/1.1/">
  <foaf:Person>
    <foaf:nick>homepw</foaf:nick>
    <foaf:name>homepw</foaf:name>
    <foaf:openid rdf:resource="http://homepw.livejournal.com/" />
    <foaf:dateOfBirth>1965-02-01</foaf:dateOfBirth>
    <foaf:page>
      <foaf:Document rdf:about="http://homepw.livejournal.com/profile">
        <dc:title>LiveJournal.com Profile</dc:title>
        <dc:description>Full LiveJournal.com profile, including information such as interests and bio.</dc:description>
      </foaf:Document>
    </foaf:page>
    <ya:blogActivity>
      <ya:Posts>
        <ya:feed rdf:resource="http://homepw.livejournal.com/data/foaf" dc:type="application/rss+xml" />
        <ya:posted>1</ya:posted>
      </ya:Posts>
    </ya:blogActivity>
    <foaf:weblog rdf:resource="http://homepw.livejournal.com/"/>
  </foaf:Person>
</rdf:RDF>

The Person resource has an openid Property whose value is obviously highly related to the URL from which the document must be retrieved.  The property is similarly no fully related to the ID of the Person instance, which has no local ID.

As far as we can tell, someone simply invented an XML format that foaf files will be obtained from a URL with pattern: */data/foaf. The main purpose in making these FOAF files available is suggested by the ya:feed markup, which denotes the FOAF URL as a resource associated with a blogging feed. Unlike the use of a Person class in the context of a PersonalProfileDocument, the Person instance in this example is merely some ready-specified markup that helps indicate some information about a blog feed (the number of posted items). This FOAF file would not seem suitable for use in an identity protocol of the type discussed in the paper. It uses the FOAF vocabulary, but it is not a "FOAF file".

> In version 1.1 of OpenID, which is what is widely deployed today, the

> OP

> wasn't actually ever sent the claimed_id. The thinking behind this was

> that OPs would then be unable to "tell" that they are being delegated

> to, and thus can't make delegation a premium service or whatever.

This comment from a related thread strongly suggests that there was an explicit design intent to create a bias against certain commercialization practices.

Meritocracy also obviously lies at the heart of the OpenID community. And, meritocracy is of course a well established means for executing a political agenda (e.g. a praxis of "anti commercialization" aimed at certain forms of identity management).

Perhaps this kind of intent needs -- and these underlying agendas need -- to be much more obvious in the marketing of the OpenID Foundation. The meaning of the OpenID Trademark may need to more clearly associated with such goals, in the mind of the average user. If the OpenID Auth 2.0 design cell decided, for example, to liberalize inherited proscriptions against certain commercializations, we the plebs need to know clearly this shift of intent occurred, for example. We cannot be expected to infer it from an engineering spec.

Once again, Peter the pleb finds no flaw in pursuing a social agenda by meritocracy politics, so long as it's mostly overt. But, the engineering specs today bear little rationale material - material that succinctly characterizes why the mechanisms are constructed so as to realize the particular set of (social/political) goals. This makes it hard to perform an analysis of the strength of the security services and hard to outline their impact.

----------

Now, playing devil's advocate:-

Would it be appropriate to characterize "OpenID" -- the movement -- in the same terms as the early-phase PGP movement? That is, its anti-RSA, anti-USG, freedom from Russian apparatchiks..., long live crypto anarchism, liberty for the web, Richard Stallman is only ever left?

If the overriding goal is to use counter-culture adoption dynamics (from the blogworld) to "let crypto be free", or "be free from CALEA spying by VOIP companies (outsourced to VeriSign)", "ensure no one can make money from offering id mgt services" ....then can we please make this more clear - in the marketing material issue by the OpenID Foundation?

If I was supposed to immediately associate the OpenID Foundation and the term OpenID with crypto-anarchism, then I didn’t get it! The clear association with blogging did raise my suspicions, early on, tho.

If it is anarchistic in spirit, then the anarchist community would need counter-assurance, given corporations like Microsoft and VeriSign are now highly lauded for their involvement in OpenID. Partly by my design, VeriSign is a company that commercially exploits a TTP brand that sells assurance of trust. Without my involvement, the business of trust marketing later evolved to mean that your certificate fee subsidizes the operation of the infrastructure for spying on your secure communications (as and when necessary, as decided by in secret by folks selected using much the same kind of meritocracy criteria that probably orchestrate the OpenID design cell).

I'd be a bit surprised if a fundamentally crypto-anarchist OpenID brand (if it is indeed crypto-anarchist in nature) would countenance associating with the particular political balance built into the modern VeriSign brand - a crafted balance between privacy and spying that allows strong consumer crypto to be determined as a "trustworthy" and "responsible" use of what was only 10 years ago a proscribed (military) munition