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Re: Should WebIDs denote people or accounts?

From: Anders Rundgren <anders.rundgren.net@gmail.com>
Date: Sat, 17 May 2014 19:27:32 +0200
Message-ID: <53779C04.90807@gmail.com>
To: Sandro Hawke <sandro@w3.org>, public-webid@w3.org
Sandro,
Well, your observations are correct, WebID doesn't make
sense for logging in to a bank.

However, the reason for that is not because a bank login denotes an "account"
(since you anyway MUST distinguish different users accessing a bank account),
the actual reason why WebID is inappropriate is that there is no point adding
a URI to web-base user data since it is anyway stored inside the bank-server.
The URI would only add authorization hassles.

TLS may be used although banks usually bypass the standard solution for the
fact that is is incomplete from their perspective including missing support
for PIN-code protected keys for on-line provisioned certificates. Netscape's
1995 two-week student hack (HTML5's keygen) doesn't really cut it.

Anders
Bank-PKI professional

On 2014-05-17 17:57, Sandro Hawke wrote:
> Summary: Most people will be unwilling to give up the idea of having 
> multiple separate accounts.  This calls into question the whole idea of 
> WebID.
> 
> First off, as an aside, hello everyone.   I was in the CG for its first 
> few weeks to help get things started, but then left when it looked like 
> things were well in hand, and I had many other W3C duties.   Since then, 
> nearly all of my Working Groups (SPARQL, RDF, GLD, etc) have wrapped up, 
> and I'm mostly doing R&D, working with TimBL and Andrei Sambra.   The 
> work we're doing needs something like WebID.
> 
> That said, I have to raise a difficult issue.   Maybe there's a simple 
> solution I'm just missing, but I fear there is not.
> 
> The examples in the spec, and what I saw from Henry when he first 
> presented foaf+ssl, show the WebID denoting a person.   In the examples, 
> it's often an instance of foaf:Person, and occurs in triples as the 
> subject where the predicate is foaf:name, foaf:knows, etc.  Also in 
> triples as the object of foaf:knows.
> 
> So that means that in RDF, my WebID denotes me.   And if I have three 
> different WebIDs, they all denote me.    Anything that's said in RDF 
> using one of my WebIDs is equally true to say using any of my other 
> WebIDs, and a reasoner might well infer it.   That's how it looks like 
> WebIDs are supposed to work.
> 
> This is in stark contrast to how most online identity systems work. The 
> usually model is that a person has an account with a particular service 
> provider.   In the old days that might have been a bank, while these 
> days it might be some kind of "identity provider" like Google or 
> Facebook.   There is important flexibility in this model.    I have two 
> Google accounts, and my kids have many among themselves, so on the 
> computers around the house, there are many possible Google accounts 
> saved as possible logins.    Behind the scenes, Google may or may not be 
> correctly inferring which humans are attached to each of these accounts, 
> but as long it doesn't get wrong which accounts can see adult content, 
> or use my credit card, or see/edit particular documents, that's okay. 
> Those important features are attached to accounts, not people, in 
> systems today.
> 
> FOAF makes this distinction quite clear, with classes foaf:Person and 
> foaf:OnlineAccount.   FOAF, quite reasonably, puts relationships like 
> foaf:name and foaf:knows on foaf:Person.   It's interesting to know my 
> name and who I know.   It might also be interesting to see which of my 
> accounts are linked with other accounts, I suppose, although that's more 
> complicated.
> 
> I'm not sure exactly why people might have multiple accounts. Sometimes 
> an account is provided by an employer or school and goes along with lots 
> of resources, but also includes restrictions on use or limitations on 
> privacy.  Sometimes an account is obtained with a particular service 
> provider, and then one no longer wants to do business with them. 
> Sometimes security on an account is compromised and a backup is needed. 
>    Sometimes one just wants to separate parts of life, like 
> work-vs-nonwork.   I've asked a few friends if they'd be willing to have 
> exactly one computer account, and gotten an emphatic "No!".
> 
> So the my question might be, can WebID allow that separation?   If 
> access control is granted by WebID (as I've always seen it done), and 
> WebID denotes a person (as I've always seen it), and the computer 
> figures out that multiple WebIDs denote the same person (as it's likely 
> to do eventually), then isn't it likely to grant the same access to me 
> no matter which of my WebIDs I'm using?   Wouldn't that be the 
> technically correct thing for it to do?
> 
> In summary: WebID is doing something quite radical in the identity space 
> by identifying humans instead of accounts.   Are we sure that's a good 
> thing?    It seems like in practice, humans interacting with service 
> providers want to have multiple distinguishable identities with separate 
> authentication.  One might try to clean this up with some kind of 
> role-based access control [1], but that might not solve the issue that 
> by having WebIDs denote people, they prevent people from authenticating 
> differently to get different access/behavior.
> 
> (It's true some identity providers, like Facebook, forbid a human from 
> having multiple accounts.  But I think in response we see humans get 
> their additional accounts by using other providers.)
> 
> The conclusion I'm tentatively coming to is that WebIDs should be 1-1 
> associated with accounts, not people.  As such, they'll be associated 
> with authentication, authorization, and profiles, as they are now.   But 
> the RDF modelling will have to be different, with things like { <webid1> 
> foaf:knows <webid2> } being disallowed.
> 
> If we're going to make a change like that, making the WebID one hop away 
> from Person, I'd suggest actually making it denote the account's profile 
> page, so that it can be a normal URL, denoting an Information Resource.
> 
>         -- Sandro
> 
> [1] http://en.wikipedia.org/wiki/Role-based_access_control
> 
Received on Saturday, 17 May 2014 17:28:11 UTC

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