[Openid-specs-ab] Identifiers and discovery.

[Breno de Medeiros]

On Wed, Apr 13, 2011 at 01:15,  <Axel.Nennker at telekom.de> wrote:
>
> Similar for me. I gave up on trying to attend because 4pm PT is 1am here, so I went to sleep at 23:30 and could have made it for midnight.
> Anyway.
>
> Regarding identifiers: Some people expect that the openid is "fancy" and easy to distiguish.
> Example: @t is much cooler than @AxelNennker or pt at fb.com is cooler than user4711 at facebook.com or
> https://me.google.com/AxelNennker is cooler than https://me.google.com/users/lasjkflasdflsajfljal02384ß20183lskadjfölsafj
>
> The uglier ones achieve the goal of beeing not reassigned much easier than the prettier ones.
>
> Display Names are an related issue: I guess that there are more than one "Mike Jones" in Microsoft possibly even more than one "Michael B. Jones". Each has a unique identifier which might be reassigned (after a grace period) to a new Michael B. Jones.
>
> This is not only a technical problem. People want the pretty identifiers.

It is a technical problem. If we label the identifiers in the protocol as:

- Identifier 1: This is persistent. Use as index in your DB. E.g: a
numeric value.
- Identifier 2: This is what the user wants you to represent him as.
E.g: a name, photo, business card, etc.
- Identifier 3: This is what the user thinks you can use to find who
he is. E.g.: an email address

> The best we can achieve, I think, is that users never see the unique, never reassigned (, maybe global) identifiers.
> And that the UI for the display names is powerfull enough to help me to find the Mike Jones I want to reach.
>
> Example: Consider a blog post with comments by openid users. The blog received a sreg fullname and the openid.claimed_id and openid.identity.
> Now it renders the fullname on the html page giving us comment by several Mike Jones. The "social" rendering would allow my user agent to render the comments from my friend list other than comments from people I don't know.
>
> Ok, this moves away from pure protocol issues and issuer policy to OC best practices and UI issues.
> I am not sure how the openid abc wg "protocol" group can solve this non technical problems.
>

No, that's the mistake OpenID2 fell into. We should have different
identifiers for different purposes so that it's foolproof how to deal
with this.

My proposal is that the identifier used in auth is number 1. You know
you can't use to do anything presentational with it.
Identifier #2 is the easiest: we return attributes at the user info
endpoint that can be used to personalize the user experience.
Identifier #3 is missing from the current drafts. I can see two
sensible approaches:

- Define a discovery protocol that starts by going to the issuer and
asking what it knows about the asserted user_id. The advantage of
doing this is that we can support both public and protected (meaning
that user needs to consent) discovery with the same set of techniques.

- Use the email or profile URL (both which will be returned as user
attributes) as discovery starting points. This has some advantages in
that we may be able to re-use some existing ideas and techniques.

Again, what we don't want is an identifier that does all three jobs poorly.

> -Axel
>
>> -----Original Message-----
>> From: openid-specs-ab-bounces at lists.openid.net
>> [mailto:openid-specs-ab-bounces at lists.openid.net] On Behalf
>> Of Breno de Medeiros
>> Sent: Tuesday, April 12, 2011 6:18 PM
>> To: openid-specs-ab at lists.openid.net
>> Subject: [Openid-specs-ab] Identifiers and discovery.
>>
>> I hope Nat's well.
>>
>> I was in a meeting at 3:00pm (that I scheduled after JBradley asserted
>> the conference call would take place as usual at 4pm). When I joined,
>> Mike Jones and Nat were dropping off the call.
>>
>> That left JBradley and I on the call. We had a discussion on
>> identifiers and discovery.
>>
>> I would like to continue this conversation via email, as it's
>> an important one.
>>
>>
>> Currently, Google's proposal on identifiers is:
>>
>> - Identifiers are unique to the user and non-reassignable within the
>> scope of the issuer. However, they need not be globally unique.
>>
>> - Id_tokens attest to the issuer and therefore provide a statement of
>> the globally unique (issuer_id, user_id) pair. If the signature is
>> based on PK, these tokens are also universally verifiable and fully
>> portable.
>>
>> Looking forward to an interesting discussion,
>>
>> --
>> --Breno
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>>
>



-- 
--Breno