Re: Missing Protocol ?

[Al Arsenault <awa1@xxxxxxxx>]

Thierry,

	I'm not sure that there is a solution for this problem that doesn't
involve knowledge external to the PKI. 

	Suppose that the fondest dreams of the early X.500 designers had come
true, and every item (to include person) in the known universe had a
globally unique name.  Even in that case, if you are working with one
"Jim Jones of GM" and not with any other "Jim Jones of GM", and you need
to distinguish them, then YOUR "Jim Jones of GM" has to tell you
out-of-band what his globally-unique name is, or at least enough
disambiguating information to let you accurately pick it out from the
entries in the global directory.  Otherwise, you'll never know which is
which.

	The same type of information can be passed to you "out-of-band" in the
current situation; when you first begin working with the right "Jim
Jones of GM", he can provide you his certificate directly, or give you
enough disambiguating information to make sure you find it somewhere
else.  If he doesn't, you're not going to work securely.  

	(All of this is a long way of saying that we're really wandering here. 
I'm not convinced that it is possible to define a technical - by which I
mean "machine-processable" - protocol that is guaranteed to find you the
right certificate if you don't have enough information from other
contexts.)

			

Al Arsenault
Chief Security Architect
Diversinet Corp.
P.O. Box 6530
Ellicott City, MD 21042-0530
(410) 480-2052

Thierry Van Doninck wrote:
> 
> Roger,
> 
> Yes,
> 
> But knowing if a certificate is valid might and trustworthy might still not tell you who it is.
> Therefor a relying party might not know wether the certified party can be allowed to perform a certain
> action. A certificate received by a RP might not contain sufficient information to authenticate
> the person behind it. (I know it is a Jim Jones working at GM., but which Jim Jones is it ?)
> 
> I as a RP can check that it is valid, I have every confidence that it is valid (after having read the Cp and CPS :-( ),
> but I still cannot USE it, because it does not tell me who is being certified. (Is it my business partner or not ?)
> 
> Thierry Van Doninck
> eMail : Thierry.vandoninck@dexia.be
> 
> ryounglove%lucent.com@Internet
> 14/04/2000 21:14
> To:     egerck%nma.com@Internet
> cc:     ietf-pkix%imc.org@Internet (bcc: Thierry Van Doninck/GKBCCB)
> 
> Subject:        Re: Missing Protocol ?
> 
> I agree with both Dave and Ed, however I do not believe that a new WG is
> needed. The individual identity (carbon or silicon life form) that is
> certified with a digital certificate is the responsibility of the PKI which
> is issuing the cert. The Certificate Policy written by that PKI operator
> supplies the requirements for identification authentication. The CA CPS
> states how the CP requirements are met. It is the Relying Parties
> responsibility to properly evaluate the validity of a certificate that they
> receive. When both the CP OID and the CPS OID is included in the cert it
> becomes easy to evaluate the validity.
> At 01:41 PM 4/14/2000 , you wrote:
> >Dave:
> >
> >Yes and to your final paragraph.  A new WG would be needed -- otherwise
> >this WG would need to backtrack so much that nothing would be left ;-)
> >OTOH, with a new WG then what this WG has done might be a *component*
> >in a bigger frame, and a useful one.
> >
> >Cheers,
> >
> >Ed Gerck
> >
> >"David P. Kemp" wrote:
> >
> > > > From: Denis Pinkas <Denis.Pinkas@bull.net>
> > > > > From: Ed Gerck
> > > > > Here, in PKIX, the main purpose of a CA is also to bind a public
> > key to the name
> > > > > contained in the certificate and thus assure third parties that
> > some measure of care
> > > > > was taken to ensure that this binding is valid for both -- i.e.,
> > name and key. However,
> > > > > the issue whether a user's DN actually corresponds to identity
> > credentials that are
> > > > > *globally* linked to a person, or to a local alias or, simply to an
> > e-mail address -- and
> > > > > how such association was verified --   is  outside the scope of
> > PKIX and depends
> > > > > on each CA's CPS.
> > > >
> > > > I am not sure that this is really outside the scope of PKIX. If some
> > > > judge would like to make the difference between John Smith 22 and
> > > > John Smith 23, what can he do ? Nothing that has been standardized
> > > > today. :-(  In PKIX we currently do not offer any solution. Maybe we
> > > > should ? What kind of solution ? Being able to get back (when
> > > > appropriate) the registration information (sometimes called the
> > > > credentials) that has been registered at the time of registration by
> > > > the RA. I do not think that it may be practical to get that
> > > > information by paper and in a different format for every CA in the
> > > > world. A protocol (and a schema) might be useful.
> > > >
> > > > Denis
> > >
> > > Denis,
> > >
> > > As long as CPSs are different, the "big identity in the sky" (the
> > > information about a subject which makes John Smith 22 different from
> > > John Smith 23) will be different, and outside the scope of PKIX.  If
> > > the judge has access to a certain body of information:  employment and
> > > credit history, property ownership and tax records, utility bills, etc,
> > > and the CA has used any of that information to establish identity, then
> > > the certificate may be useful to the judge.  If the CA uses only email
> > > address to establish "identity", the certificate will be useless to a
> > > judge dealing in non-electronic matters.  I don't see how PKIX could
> > > consider in-scope an effort to develop a schema for the universe
> > > of information which could constitute a human identity.
> > >
> > > Dave
> 
> ---
> TTFN
> Roger W. Younglove, CISSP
> Sr. Network Security Consultant
> NetworkCare® Security Services
> 100 Galleria Officentre, Ste. 200
> Southfield, MI 48034
> Numeric page: 888.935.6755
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