Requiring Pseudonymous Identifier

[Andrew Arnott]

 leaves out the scenario of unsolicited assertions.A new directed identity
value that the RP passes to the OP to indicate it wants a psuedononymous
identifier.  Consider this:

An OP needs to perform RP discovery (already), and probably does so before
sending an unsolicited assertion in order to find out what the assertion
receiving URI would be for a given realm.  DNOA does this already.  If that
RP's XRDS document included a TypeURI element that had a special
psuedononymous-identifier-only-please value the OP could pick up on this,
and send the unsolicited assertion using the appropriate type of claimed_id.

Likewise, when an RP sends an ordinary directed identity request to an OP,
the OP would again notice the RP's XRDS during RP discovery and see what
kind of identifier the RP wants and assert accordingly.

Yes, some OPs won't honor the RP's wishes, and some OPs don't do RP
discovery at all.  Perhaps to help the RP detect whether the OP respected
its wishes would be to send a PAPE extension or some other openid.*
parameter to say "yes, this is a pseudo- identifier."  RPs have no way to
analytically be certain that some identifier is psuedononymous anyway, so
ultimately the RP has to trust the OP (whether implicitly or through a white
list is up to the RP).

--
Andrew Arnott
"I [may] not agree with what you have to say, but I'll defend to the death
your right to say it." - Voltaire


On Wed, May 13, 2009 at 8:44 AM, George Fletcher <gffletch at aol.com> wrote:

> I don't think OpenID should specify how pseudonymous identifiers are
> generated. That should be up to the OP. But I like the idea of using a fixed
> URI as the claimed_id value to specify the behavior desired by the RP. If,
> however, we need to grow this to cover anonymous based identifiers (i.e. the
> claims based models from earlier in this thread) then it might make sense to
> look at a PAPE extension that covers the type of identifier requested.
>
> Thanks,
> George
>
>
> Nat Sakimura wrote:
>
>> Sorry for a slow response. This week is especially busy for me...
>>
>> I borrowed the notion from Austrian Citizen ID system.
>> In there, the services are divided into "sectors."
>> A sector may span several agencies.
>> They call ID as PIN (Personal Identification Number).
>>
>> There is a secret PIN (sPIN) which is not used anywhere but in their
>> SmartCard.
>> Then, sector sepcific PIN (ssPIN) is calculated in the manner of :
>>
>> SHA1(sPIN + SectorID)
>>
>> (Note, there is a bit more details but...)
>>
>> I have thrown OP secret into it.
>> To avoid the analytic attack, I agree that it is better to use
>> individual secret, as some of you
>> points out.
>>
>> Regards,
>>
>> =nat
>>
>> On Tue, May 12, 2009 at 5:55 PM, Dick Hardt <dick.hardt at gmail.com> wrote:
>>
>>
>>> On 12-May-09, at 1:36 AM, Nat Sakimura wrote:
>>>
>>>
>>>> Reason for using RP's Subject in XRD instead of simply using realm is
>>>> to allow for something like group identifier.
>>>>
>>>>
>>> would you elaborate on the group identifier concept?
>>>
>>>
>>>
>>>> This is just one idea. Downside of this approach
>>>> is that we need to set up a WG.
>>>>
>>>> I am sure there are more ideas. It might be possible to utilize AX
>>>> so that it will only be a profile that does not require a WG.
>>>>
>>>> So shall we start discussing which direction we want to go forward?
>>>>
>>>>
>>> sure!
>>>
>>>
>>>
>>
>>
>>
>>
>>
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