[OpenID] Too many providers... and here's one reason

[George Fletcher]

Per Dick's response earlier in the thread, I don't see why using an OP 
of my choice with a third party asserted attribute of my membership in 
org XYZ isn't sufficient to meet this use case.

Basically, I'd use my preferred OP and request the organization to 
provide a signed attribute of my membership in org XYZ. Then when I log 
into the RP (with the OP of my choice), it can request this attribute 
and I can choose to provide it (or not) at time of authentication.

This should be completely doable with the existing OpenID 2.0 and 
Attribute Exchange specs. Is the issue what Peter mentioned that there 
aren't many AX supporters right now?

Of course, there will have to be a "trust relationship" between org XYZ 
and my preferred OP, but I don't see that trust as any deeper than the 
"trust relationship" between and RP and an OP.

Thanks,
George

Andrew Arnott wrote:
> You're affirmative action example is well taken.  Obviously if an OP 
> is the best solution we should go with it.  But just imagine what all 
> these spoons of sugar are going to do to me...
>
> Suppose I'm a member of 15 organizations (that's conservative) between 
> my professional, social, personal lives.  Some RP could be interested 
> in providing specialized services if I am a member of Org XYZ. 
>  Another RP may offer premium services if I am a member of Org ABC.
>
> Now if every org I am a member of became an OP, then my identity XRDS 
> file now has at least 15 providers listed.  Powerful, perhaps. 
>  Dangerous: yes!!!  If OpenID's weakness already was that if an OP was 
> compromised then all Identifiers that allow that OP's assertions are 
> now compromised, then that weakness is proportional to the number of 
> OPs that are listed in my XRDS file.  I for one do NOT want 15 
> Providers listed in my XRDS file.  There was a time I thought more was 
> better, and to date I have some 5-6 OPs listed, but I've considered 
> narrowing that down to just 2-3 to decrease my risk surface area.
>
> Using OAuth as a post-authentication step of confirming membership is 
> an interesting idea and should work.  In the end, whether we use 
> OpenID or OAuth, it seems we're mixing authentication and membership, 
> or authorization and membership, in order to just get membership.  Too 
> bad there's not just a way to get "membership".
>
> Yes, InfoCard managed cards solve this problem, although not as 
> implicitly as I'd like.  I'm hoping OpenID can have a solution of its own.
>
> On Mon, Sep 15, 2008 at 5:12 PM, Eran Hammer-Lahav 
> <eran at hueniverse.com <mailto:eran at hueniverse.com>> wrote:
>
>     This is like applying affirmative action to cooking. "This cake
>     calls for two spoons of sugar but we don't have enough people
>     using lard in cakes, so I am going to use it instead..."
>
>     Looks like they want to use OpenID as an assertion verification
>     protocol, allowing them to confirm that a given user is in fact a
>     member of their organization. If all they want to do is assert the
>     claim, they can use both OAuth and OpenID, each with a different
>     set of extra features. If they use OpenID, a side-effect of this
>     will turn them into an Identity Provider, but if this is not their
>     intention, they should not use that identifier internally, but
>     instead accept OpenID.
>
>     In other words, they should be an OP for assertion verification,
>     and RP for site login.
>
>     EHL
>
>
>
>     On 9/15/08 4:45 PM, "Andrew Arnott" <andrewarnott at gmail.com
>     <http://andrewarnott@gmail.com>> wrote:
>
>         I just spoke with an organization that wants to become a
>         Provider so that other RP web sites can specifically tell if
>         the logging in user is a member of this organization by
>         whether their OpenID Identifier was asserted by that org's OP.  
>
>         Ideally, I'd like this org to choose to be an RP instead of an
>         OP because there are already too many OPs out there and not
>         enough RPs, IMO.  
>
>         How can an RP accept an OpenID Identifier from arbitrary OPs,
>         but at each login determine whether the Identifier represents
>         a user who belongs to a particular Organization?  Basically
>         the Organization needs to send an assertion about the
>         Identifier's membership, but only be willing to do so if that
>         identifier is confirmed as having logged in successfully to
>         that RP.  This would be easy to do if that Org was an OP, but
>         I'm trying to reduce the # of reasons to be an OP.
>
>
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