Name Uniqueness Problem - Can OpenID solve it?

[John Kemp]

Hi Joaquin,

I agree with your analysis - the conclusion of which is that the term
"unique identifier" is misleading, even when used as shorthand for "an
identifier that unambiguously identifies an entity in a set of entities".

In which case, I'll re-state what I said before:

OpenID is mostly concerned with identifying an entity that has an
account with an OpenID IdP. In such cases, the IdP (not the user) will
have to create an identifier that is unambiguous in that context. Making
such an identifier in a way that a human will understand or remember it
is likely to be a hard problem to solve (see bank accounts, credit cards
et al.)

As I already stated, I don't think a user should really need to know
such identifiers.

- John

Joaquin Miller wrote:
> 
>> There's a difference between an identifier, a unique identifier, and ...
> 
> What Ben and Alexis wrote is correct.  In his message, John uses a term
> that many folks use in our common parlance: 'unique identifier'.  John
> explains several practical matters about the use of names.  I don't
> question his analysis: he explains some important matters and explains
> them clearly.
> 
> But I sure don't like the term he chose to use.
> 
> I feel strongly we should never use 'unique identifier', no matter what
> meaning we intend.  This term only promotes misunderstanding.
> 
> There is a well established technical meaning for 'identifier' and we
> should stick to it.  This meaning not only suits our technical
> requirements, it suits the shared understanding of the general population.
> 
> 12.1 Name: A term which, in a given naming context, refers to an entity.
> 12.2 Identifier: An unambiguous name, in a given naming context.
> 12.3 Name space: A set of terms usable as names.
> 12.4 Naming context: A relation between a set of names and a set of
> entities. The set of names belongs to a single name space.
> 6.1 Entity: Any concrete or abstract thing of interest.
> 
>      -- X.902 | International Standard 10746-2
>          http://www.joaquin.net/ODP/
> 
> It means that there are no identifiers except in relation to a naming
> context.  With respect to a given naming context, an identifier is a
> name for a single entity.  If, in a given naming context, a name refers
> to two or more entities, that name is not an identifier.
> 
> Cordially, Joaquin
> 
> 
> I feel it would be a waste of our time, but if challenged I can quickly
> demonstrate that there is no such thing as an identifier that is
> unique.  My point about 'unique identifier' is that it muddles the
> conversation and sows confusion.  But another point is this: It's not
> useful to call an identifier that is not unique a 'unique identifier'.
> 
> 
> 
> 
> 
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