Subject: RE: Global unique identifier

From: [email-masked]
Date: Wed, 12 Apr 2000 11:16:18 -0400

Robert Moskowitz <[email-masked]> on 04/12/2000 10:42:00 AM

To:   Anders Rundgren <[email-masked]>, "'Denis Pinkas'"
      <[email-masked]>
cc:   "[email-masked]" <[email-masked]>
Subject:  RE: Global unique identifier

At 03:29 PM 4/12/2000 +0200, Anders Rundgren wrote:

>Essentially only one per country at maximum.   Companies etc. and
commercial
>issuers like VerySign will use CA-specific naming domains I suppose?

No.  Get real.

A GUI would perforce be the IssuerName concatenated with the SubjectName.

[Tom Gindin]   A pre-existing GUI would not have to be based on the
IssuerName, nor would it necessarily contain the entire subject name.  It
could be (in the USA) a Social Security number (country + ID value) or an
employee ID (organization + ID value) - although Social Security numbers
might get banned by privacy legislation.  Only if the CA itself assigned
the GUI would the IssuerName be a mandatory component.

I can even seen problems there, wtih WTO or WIPO hving to deal with suits
and counter suits between CAs that use the same name.  At least with DNS we
stopped the independent root efforts.

[Tom Gindin]   Identical DN's for independent issuers would cause very
severe problems with the current standards, starting with CMS SignerInfo.
These proposals would not introduce any new limitations in that respect.

Robert Moskowitz
ICSA
Security Interest EMail: [email-masked]

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From: "Christopher Williams" <[email-masked]>
Date: Wed, 12 Apr 2000 16:58:54 +0100

There aren't many details about a person that can be assumed to be constant
(not even his / her name).  Certainly not his subject name as that
presumably changes when the person changes job.  The US has a social
security number; other countries have similar schemes (I have a unique
National Insurance number).  If there are privacy issues surrounding the use
of these values, use a SHA-1 hash of the value instead.

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From: Paul Koning <[email-masked]>
Date: Wed, 12 Apr 2000 12:02:10 -0400

>>>>> "Christopher" == Christopher Williams <[email-masked]> writes:

 Christopher> There aren't many details about a person that can be
 Christopher> assumed to be constant (not even his / her name).
 Christopher> Certainly not his subject name as that presumably
 Christopher> changes when the person changes job.  The US has a
 Christopher> social security number; other countries have similar
 Christopher> schemes...

Just to repeat what has been said before:

a. The US SSN is *not* a globally unique identifier.  It is an "almost 
always unique identifier".

b. The US SSN is not necessarily constant for a given person.  There
are conditions under which a person can obtain a new SSN.  Given the
increased use of the SSN for dubious purposes (e.g., for insurance ID
numbers, student ID numbers, and other things of questionable
legality) the incentive for SSN abuse is increasing dramatically.
This in turn will cause the rate of SSN change to increase (since SSN
abuse is one of the recognized grounds for getting a new one).  (FYA,
having an SSN that contains the string "666" is another.)

	paul

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From: Sam Schaen <[email-masked]>
Date: Wed, 12 Apr 2000 12:15:45 -0400

> of these values, use a SHA-1 hash of the value instead.

Since the number of possible values is limited (e.g., 10**9 for U.S.
Social Security Number), it is feasible to precompute the hashes for all
possibilities and do a lookup.  So privacy is minimal.  On the other
hand, few people believe the SSN is very private these days.

Sam Schaen
MITRE Corp.