Re: Browser UI & privacy - a discussion with Ben Laurie

On 10/5/12 8:18 AM, Henry Story wrote:
> On 5 Oct 2012, at 13:58, Kingsley Idehen <kidehen@openlinksw.com> wrote:
>
>> On 10/5/12 3:08 AM, Hannes Tschofenig wrote:
>>> Dick,
>>>
>>> you have to see this from a computer science perspective.
>>>
>>> Think about a relational database system. You have one or more tables in each database with columns. The columns represent the attributes that are stored about you. Rows are specific instances (values) for these attributes.
>>>
>>> Different systems (with their databases) store different data about you. Even though there is from a philosophical point of you only one Dick Hardt each of these system only see a small subset of the attributes of you.
>>>
>>> The index, the unique key, is the identifier and is (of course) an attribute itself. This makes the crisp separation of identity and identifier somewhat difficult.
>>
>> Only because you are using an extensional system for your example.
>> The identifier in your example is an extension of the data that makes the record. An intensional system wouldn't have such a limitation which is basically what graph / object model DBMS engines bring to the table. This is what Object Identity [1] in the object manifesto of yore was all about.
> I am not sure how intensional and extensional come into play here? Can you point me to SemWeb documents on this?

Truth statements, claims, or propositions == intensionality. Hopefully, 
you can see that the entire Semantic Web Project is about applying 
intensionality at Web-scale.

My comment (as per my references) were more to do with building on the 
RDBMS (an extensional system re. identifiers e.g., primary keys) 
anecdote. A WebID, for all intents and purposes, is a Web-scale "super 
key" that's verifiable via the use of a protocol (the WebID 
authentication protocol)  that leverages the combination of 
cryptography, entity relationship semantics, and logic.

>
> But I can try to get it from first principles.

Yes, do that then :-)

>
> The extension of a one place predicate P in logic is the set of objects that satisfy it. So for Giraffe it
> is the set of Giraffes.  Hence if Sophie is a Giraffe, then Giraffe(Sophie) is true off Sophie is
> in the set of Giraffes.
>
> For foaf:knows which is a relation (== a two place predicate) the extension is the
> set of pairs of people who know each other.
>
> The Intension is the definition of the term, or perhaps something like the way of
> knowing  that something  is in the set of things for which it stands. In the
> semantic web/Linked Data/Web space the  meaning of a URI is given by the document
> returned on dereferencing it. That gives the canonical meaning for the URI.
>
> So yes, the Web has a way of finding the definition of a URI for a URI, and that is what
> OpenID uses in fact when on dereferencing a webID document the Relying party finds a relation
> such as:
>
> <> openid:provider <http://some.big.provider.com/auth?>
>
> The openID <> is the document that defines what it is about. Hence it can define that it is
> an openid profile and that it delegates authentication to the provider.
>
> With WebID we have just removed the need for the provicer, by using Cryptography.
>
> So yes, the intension/extensional issue does help make sense of this. But it's a bit concise
> in your explanation above.

I am trying to be concise, and deliberately so. I also provided 
reference links since my response (as already stated) was to an RDBMS 
oriented anecdote.


Kingsley
>
>
>>>   Of course there may be more than one key that identifies you within that system. Hence, sharing the attributes with other parties may then allow them to uniquely identify you (with a certain probability) even though you never disclosed the unique key.
>>>
>>> Hope that this makes sense.
>> Yes, but within confines of an extensional system. In an intensional system every record is a proposition. Basically, this is the model upon that drives the Semantic Web, Linked Data, and  WebID.
>>
>> Links:
>>
>> 1. http://www.cs.sfu.ca/CourseCentral/354/zaiane/material/notes/Chapter8/node8.html
>> 2. http://www.cs.cmu.edu/afs/cs.cmu.edu/user/clamen/OODBMS/Manifesto/htManifesto/node4.html#SECTION00022000000000000000 .
>>
>> Kingsley
>>> Ciao
>>> Hannes
>>>
>>>
>>> On Oct 4, 2012, at 8:26 PM, Dick Hardt wrote:
>>>
>>>> … a somewhat tangential comment.
>>>>
>>>> On Oct 4, 2012, at 8:10 AM, Hannes Tschofenig <hannes.tschofenig@gmx.net> wrote:
>>>>
>>>>>    $ Identifier:   A data object that represents a specific identity of
>>>>>       a protocol entity or individual.  See [RFC4949].
>>>>>
>>>>> Example: a NAI is an identifier
>>>> Easy to  agree to.
>>>>
>>>>>    $ Identity:   Any subset of an individual's attributes that
>>>>>       identifies the individual within a given context.  Individuals
>>>>>       usually have multiple identities for use in different contexts.
>>>>>
>>>>> Example: the stuff you have at your Facebook account
>>>> Not so easy to agree to.
>>>>
>>>> I would argue that your identity is everything about you, your Facebook data being part of your identity. Saying I have multiple identities is confusing. There is only one of me. Any slicing becomes challenging as there are no sharp lines between who I am on Facebook, Twitter, Google+ or LinkedIn. There is lots of overlap.
>>>>
>>>> -- Dick
>>>
>>>
>>
>> -- 
>>
>> Regards,
>>
>> Kingsley Idehen	
>> Founder & CEO
>> OpenLink Software
>> Company Web: http://www.openlinksw.com
>> Personal Weblog: http://www.openlinksw.com/blog/~kidehen
>> Twitter/Identi.ca handle: @kidehen
>> Google+ Profile: https://plus.google.com/112399767740508618350/about
>> LinkedIn Profile: http://www.linkedin.com/in/kidehen
>>
>>
>>
>>
>>
> Social Web Architect
> http://bblfish.net/
>


-- 

Regards,

Kingsley Idehen	
Founder & CEO
OpenLink Software
Company Web: http://www.openlinksw.com
Personal Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca handle: @kidehen
Google+ Profile: https://plus.google.com/112399767740508618350/about
LinkedIn Profile: http://www.linkedin.com/in/kidehen