Subject: Re: PKI International Consortium

From: [email-masked]
Date: Sat, 3 Apr 2004 08:21:17 -0700

An example with slight variation on this was some EU directive that
electronic payments at point-of-sale should be as anonymous as cash, aka it
should be possible to authenticate a transaction for authorization w/o
requiring any identification what-so-ever.

The issue is that if you have some sort of authentication, aka "something
you have", "something you know", "something you are" .... and possibly
non-shared-secret based ... it is possible to have an authorization context
that just does authentication and no identification is involved.

it that case, if there is an authorization context ... with some recorded
authentication mechanism ... then the authentication is bound to the
authorization context and there is no identification at all.

in such a taxonomy .... a certificate represents a static, stale,
authorization context for offline environments ... where the public key is
the authentication mechanism bound to the authorization context. The
authentication mechanism is some form of "something you have" .... based on
uniquely having a private key that generates a digital signature that can
authenticated with the public key. This is basically the scenario for the
relying-party-only certificates from the mid-90s (somewhat resulting from
retrentching from the horrible privacy issues of full blown x.509 identity
certificates). Note, however, it isn't the certificate that creates the
"something you have" associated with the private key, the certificate
provides the portable, stale, static authorization context for offline
environments. It is equally possible to have an online environment where
the public key is bound to an online authorization mechanism and no
certificates are involved at all.  The online payment point-of-sale
transactions with relying-party-only certificates exemplified redundant and
superfluous. The transaction was valuable enough that timely and aggregated
online information was deemed justified (the benefit of having an online,
timely transaction more than offset the incremental cost of having an
online transaction)  .... but a relying-party-only certificate was provided
such that their could be an offline authorization context .... but that was
then made redundant and superfluous by having the transaction executed
online with an online authorization context.

The example I've used for identity is the problems with issuing SSL server
domain certificates. The authoritative agency for domain names is the
domain name infrastructure. The typical process for obtaining an SSL server
domain certificate is to provide very strong identification information to
the SSL certificate issuer. The issue is that the domain name
infrastructure has some identification information registered for the owner
of the domain name. The challenge for the SSL certificate issuer is to be
able to perform some level of identification matching from what is provided
by the certificate applicant with the identification that is on file for
the domain name owner. The reason for the identification operation is that
there is no industry-specific authentication.  This turns out to be
expensive and somewhat error prone.  A suggestion, somewhat from the
certificate industry is that a public key is registered with the domain
name infrastructure when the domain name is registered. Then when somebody
applies for a certificate, they digitally sign the operation. The
certificate issuer then just needs an online authentication of the digital
signature with what is on file with the domain name infrastructure and a
very expensive and error-prone identification process is turned into a much
simpler industry-specific authentication operation. There is an implied
authorization that the owner of the domain name is allowed to obtain an SSL
domain certificate for that domain name. Of course, there is possibly a
slight Catch-22 for the SSL certificate industry ... that if the
certificate industry can make use of online public keys from the domain
name infrastructure .... that possibly the rest of the world could also ...
leading to possibly eliminating the need for SSL domain name certificates
with stale, static certificates binding public keys to domain names.

[email-masked] on 4/2/2004 8:49 pm wrote:

I am in complete agreement with you, Lynn.  An industry-specifc
identity should be designed to perform only a single function -
authenticate the holder of the credential.  Authorization must
ALWAYS be determined by the context that has successfully
authenticated the entity - and those authorization rules must
always be owned and controlled by the context owner.

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

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From: "todd glassey" <[email-masked]>
Date: Sun, 4 Apr 2004 15:02:28 -0700

Lynn - good commentary - but I also want to add that cash transactions are
not anonymous in that they leave finger prints and they survived this
"reduction in their anonymity" after the adoption of fingerprinting by law
enforcement... i.e.  Someone handles the money and there is all kind of
tangible evidence left, the issue is the cost of collecting and maintaining
it.

Todd