Re: [foaf-dev] fidelity vs idiom

-----Original Message-----
From: Melvin Carvalho [mailto:[email protected]]
Sent: Wednesday, November 24, 2010 9:10 AM
To: Peter Williams
Cc: Dan Brickley; foaf-dev Friend of a
Subject: Re: [foaf-dev] fidelity vs idiom

On 24 November 2010 17:37, Peter Williams <[email protected]<mailto:[email protected]>> wrote:
>
>
> -----Original Message-----
> From: foaf-dev-bounces-RyYwo1q5J+qsOXdr9/[email protected]
> [mailto:foaf-dev-bounces-RyYwo1q5J+qsOXdr9/[email protected]] On Behalf Of Dan
> Brickley
> Sent: Wednesday, November 24, 2010 8:12 AM
> To: Rinke Hoekstra; Ian Davis
> Cc: foaf-dev Friend of a
> Subject: [foaf-dev] Implying that two mentioned individuals are distinct...
> updating best practice from owl:differentFrom to
> owl:IrreflexiveObjectProperty?
>
> From discussion here at benelux semweb meetup in Amsterdam -
>
> In FOAF, if we say
>
> alice a foaf:Person .
> alice foaf:knows bob .
> bob a foaf:Person .
>
> this implies the existence of ...
> ...
> It's truth doesn't guarantee formally that there are ...
> and that this doesn't put the idiom into OWL Full.
>
>
> One of the things Henry and I used to argue about was whether a FOAF file
> (used in a FOAF+SSL context) was an assertion; similar to a SAML assertion.
> The argument for assumed that because the basis of FOAF (RDF) was formal and
> logical (and capable of making assertions), so too was FOAF; and a FOAF file
> signaled via FOAF+SSL is thus an assertion. At the time of initial
> communication using mainstream SSL, it's an authenticated assertion
> furthermore.

I think a foaf file CONTAINS a set of assertions (similar to SAML).

Indeed. A SAML response msg (the container) contains values in a type language, which may or may not be assertion(s), which may or may not be true, which may or may not be trustworthy, which may or may not be faithful (have fidelity) to an overarching set of principles.

Those assertions can be true or not.  The way you normally dereference
them is HTTP vis DNS which means if you trust the server to serve you
good content, you can trust the assertions in the file.

Three ideas are present, above: truthfulness of the assertion, the notion of the trustworthiness of the "bearer" implying trustworthiness of the assertion (whether true or not), and the tying of dereferencing [names] to the evaluation of bearer trust, specifically.

Within the SAML space, that package of notions is only one of the formalized/specified models of fidelity. It's the simplest, finding applicability in a phone sending a compressed msg of (non-XML) SAML statements over a 302 redirect channel, relying on the fact that the cell tower and landline trunking system is a "bearer" ...because SS7 naming/addressing and GSM's roaming crypto  authenticates the device's transport channel to the downstream web server.

One assertion is that a Person has a specific public key.

In neither PKI nor SAML, that statement is not made (as stated). Rather, they state: a person is related to a public key. You may or may not has/have the key. I don't have my public key, when I sign emails (its stored and used at the webmail server, somewhere in hyperspace).

Using SSL you can assert that your client also has that public key and
prove it using PKI.

Here we agree, that (mainstream) SSL is about evidence and proof - whereas SAML/FOAF are mostly about assertions and trust (and have fidelity as a adjunct notion). And, indeed, if SSL is the bearer of a SAML message with its (true) assertions (specifically), one can get to fidelity.

But here is where it gets interesting: as it's not the evidentiary/proof-providing properties of SSL that derives the bearer's fidelity properties. The fidelity come from the (static) formal basis of the type system's design (the "assertion framework"), not the attachment of a dynamic proof (whose basis must be established, in its own right).

So, whereas "transitive trust" and "trustworthiness" might require evaluations based on recursive expressions and meta-reasoning, fidelity does not. Fidelity and trust are not the same, by this distinction.


In that way you can tie your client to assertions in that FOAF file.
The implication is that other assertions nearby using inked data
principles, carry a similar degree of trust.

But, all this tie-ing, and implication, seems very loose. At its heart, it basis is personal knowledge (e.g. the pgp model), and locality (e.g. meetups in the locale "Amsterdam"). This doesn't scale - for the purposes of $10 commerce.

I think that's roughly right ...

The language of fidelity needs to be model-independent, I'll say. It doesn't have to be formal, however (it can still be as it is in the world of equitable reasoning systems a semi-formalized set of intuitions about relationships, involving right and wrong vs trust and false).

It's a dangerous field. Just as fidelity is "about" trust, so faith is "about" fidelity - at which point right and wrong becomes a matter of dogma vs intuitions that serve dispute resolution.

But, at least dogmas scale, socially.

>
> If FOAF is only an idiom (albeit one with intuitive semantics about its
> pseudo-assertions of identity when used in the FOAF+SSL context) then the
> proposed relationship attributes (when invoking the powers of less than
> OWL-FULL) are not "legally sound" - having not formal basis of truth that
> meets criminal law standards. They may be circumstantially sound, which may
> well meet the legal standards for truthful assertions used typically in
> resolving civil disputes (which much more interesting to the web, of
> course).
>
> Though forlorn, a middle ground of legal semantics exists: known as equity.
> It stands between criminal and common law. About the only place its relevant
> today is in really old-fashioned trust instruments, using archaic language
> mostly. These are often found in legacy social structures, such as mortages
> and land dealing. Posh lawyers trudged out of the American law schools and
> used to invoking the phrases of the   17th and 18th century seem to like to
> invoke these language forms, I've noticed; alluding to (and only "alluding
> to") legal reasoning powers that derive from the rather abstract equitable
> principles  referenced by all the code words.
>
> So, if FOAF as it stands is suitable for the non-criminal law tradition
> (common law), and FOAF with OWL FULL would be suitable for the criminal law,
> then perhaps FOAF's idioms augmented with some OWL constructs might be
> suitable particularly for making statements about the world of trust and
> equity - statements that are "about identity" (merely).
>
> Of course, FOAF is no longer an idiom - once augmented like this. To be
> honest, I don't know the correct term for what kind of language FOAF is, if
> augmented with such equitable reasoning. Perhaps it's now a "fidelity"
> language (vs a mere idiom).
>
>
>
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