Subject: RE: Cert binding to ?

From: Alan Lloyd <[email-masked]>
Date: Thu, 4 Mar 1999 17:46:18 +1100

Some thoughts

Its a fact of life that service uses have to be bound to service
providers by something (eg phone numbers, amex cards, visa , frequent
flier numbers, etc, The names that one gets for using the service has to
comply to the engineering ideology and investment of that used by the
service provider.

In the case of X.509 certs - it is part of the directory standards -
which is a name based transaction system. However, the names one uses is
that as determined by the service provider who wants to bill you at some
stage.

the directory service of usage of DNs does not mean that the system is
geopolitical. Its just many have seen X.500 as too big (12 mb) DAP as
too big (130 kb), that X.500 is THE global directory not A directory
service, one of many) and that PKI roots = directory roots, etc.

I am sure if one presented the requirements of flexible name policies
for certificates eg cert attributes, then the technology could
accommodate them some how.

But that is up to the service provider concerned of course.
regards alan 

----------
From: Martin Smith
To: PKIX list
Sent: 3/3/99 2:05:45 PM
Subject: Cert binding to ?

Please excuse the naive and perhaps slightly off-topic intervention, but
I can't shake the feeling that more thought needs to be given to what a
certificate is being bound to.  I have become thoroughly disenchanted
with DNs, or names for that matter, in any namespace scheme.  Consider
the increasing irrelevance of political boundaries; the transience of
employment status, not to mention the rise of self-employment.  After
all, the idea of an heirarchcal namespace seems to have been a device
simply to assure uniqueness under distributed management. What a lot of
baggage for that end!

Leaving aside the naming issue, it seems that the heart of what PKI
should be about (if it is to make the cost/benefit cut) is binding an
assertion or value to a key.  The commonest "assertion" of interest
seems to be identity.  But what is identity?  As a guy named "Smith", I
have to tell you it's not enough to know my name to know who I am or to
find me.  Cutting to the chase: binding to identity comes down to
"binding to the meat".  In the end, identity binding means I anticipate
the need to apply physical compulsion to the object of my interest.  I
want to be able to put him in jail, or ship him out of the country.  The
obvious binding for identity is therefore to a (digitized) physiological
characteristic: fingerprint, retinal scan, DNA.  And by the way:
uniqueness is pretty much taken care of, too.  No problem to add a
handle for user-friendliness.  Mine's Mike Smith and this is my partner,
Jane Doe.

The other bindings of interest are to attributes:  a Swiss account
number; a surety bond; a role (supervisor; treasurer; judge.)  These may
often be attached to a meat binding, but not necessarily.  Why not be
able to open an account anonomously, receive a key for that account, and
present the key to make a withdrawal.  The DEA might care who you are,
but the banker should not. And why should a role be bound to a person?
Why not to a process?

Moving right along, what does this line of thinking imply for the matter
of transitive trust (cross-certificates?)  Most of the time I hear
people (who are actual or prospective CAs/RAs) talking about trusting a
foreign certificate they mean they trust that the other CA has made
reasonably sure the holder is (or recently was) an employee of the other
CA's company.  Generally the name is not meaningful (to the local CA;
perhaps it is to the ultimate relying party if it's an e-mail
correspondence.)  And generally other attributes (like: is the person an
employee, or just a contractor?  Cleared for SECRET?; authorized to make
purchases?) are not known.  To do real business (not supported by a web
of other, non-electronic information) you need the attribute bindings.
Most certainly making inferences from a DN is hazardous.  My only point
here is that for a given transaction, you will typically need a cluster
of bindings, and that those bindings will have different trust paths
leading to CA's that are in charge of (that is, they warrant with
effective recourse for the relying party) different assertions or
values.  In other words, fussing about naming schemes is is distraction.

Martin Smith (or not)

---

From: Martin Smith <[email-masked]>
Date: Thu, 04 Mar 1999 21:13:19 -0500

It seems to me that the problem with the X-standards was not that they were
too complex, but that they were being run by the wrong people.  It's been
observed more than once that the "lightweight" in LDAP is fast disappearing.
And why not, with RAM at $1/meg and disk at $100/gig?  The reason LDAP
succeeds is "running code and rough concensus."

Alan Lloyd wrote:
snip

> snip