Subject: Re: Identity (was PKI International Consortium)

From: [email-masked]
Date: Sun, 4 Apr 2004 20:57:59 -0600

I've lately been busy working on X9.99 financial industry financial
standard for privacy, learning more than i want to do about EU-DPD, GLB and
HiPPA, etc. Somewhat to complement the merged security taxonomy & glossary
work
http://www.garlic.com/~lynn/index.html#glosnote

I've started a merged privacy taxonomy & glossary ... pulling from EU data
privacy directive, GLB, HiPPA, OMB, FTC and a couple others.

My earlier statement was that there was significant retrenchment from the
X.509 Identity certificates of the early '90s because of the serious
privacy issues that the information represented. The issue wasn't so much
what features in X.509 Identity certificates were related to identity ...
but what features in X.509 identity certificates that raised serious
privacy issues. EU-DPD, HiPPA, and GLB have issues about PHI (protected
health information) and PII (personally identifiable information) and
sensitive perosnally identifiable information.

From their standpoint, it isn't so much identity information per se ... it
is any kind of personal information that adversely affect a person's
quality of living (like fraud, phishing, identity theft, etc).

In the past i've defined a taxonomy for authentication information and
certificates. In effect, there is some entity information that is
registered someplace ... likely at a certificate issuer ... but possibly
someplace else. The certificate issuer packages up a R/O copy of that
information and creates a static certificate containing that information
and distributes it (or at least returns the r/o copy of the information,
i.e. the certificate to the entity requesting the certificate). The
certificate by its very nature is static ... the digital signature of the
certificate issuer goes to a great deal of trouble to establish it as
static (and if it ever does change ... the certificate becomes invalid).

The certificate is, in a way, a high-integrity, static, r/o cached copy of
some information stored some place else. This allows it to be used in an
offline process when the relying-party doesn't otherwise have recourse to
the original information.

In that sense, it is directly analogous to CPU r/o cached entries, or
filesystem r/o cached records, or database r/o cached entriess.

Once the cached copy (certificate) is distributed, it by definition is
stale ... representing the state of some record at some time in the past.
The information contained in the cached certificate/copy may or may not be
stale, but by definition the certificate itself is stale.

So therefor, I assert that it is perfectly reasonable to refer to
certificates as static and stale (regardless of whether or not the
information contained within the certificate has yet become stale).

One point in using the characteristics static and stale to describe the
certificate paradigm .... is to highlight that certificates are in effect,
r/o cached entries of some other information. It makes a distinction
between the information that might be contained in a certificate from the
certificate paradigm itself. There has been a lot of work on the basic
nature of cached information ... which i believe is applicable to the
certificate paradigm. That work is totally orthogonal to the nature of the
information itself (that might be contained in a certificate).

[email-masked] wrote:

Well, my opinion is that you won't have much luck dealing with "Identity
issues" until you have a good definition of "identity".

Here's my shot at it.  If you start from the premise that identity is
just a set of attributes, then your identity is those attributes that
are constant and last forever.

So, my "Identity certificate" asserts an association between me and
the University of Wisconsin.  Is that part of my identity?  It depends
on how you interpret that assertion.  If you interpret it as "was at
one time affiliated with that university", then that lasts forever and
it is (Winston Smith to the contrary).  If you interpret it as "is
currently affiliated...", then it isn't.

The only observation I can make right now is that with the former
interpretation, Lynn Wheeler doesn't get to use the adjectives "stale"
and "static".  Whether that's any more useful than counting angels
dancing on pinheads remains to be seen, I suppose.

--
Internet trivia, 20th anv: http://www.garlic.com/~lynn/rfcietff.htm