On Wed, 14 Dec 1994 15:44:54 GMT, Stephen Farrell said:
ClearanceSyntax ::= BIT STRING {
topSecret (0),
secret (1),
confidential (2),
restricted (3),
unclassSensitive (4),
canadaProtectedC (5),
canadaProtectedB (6),
canadaProtectedA (7),
companyProprietary (8),
unclassified (9) }
Steve Kent and others could provide much more information on what can be done
in this area, but this approach certainly doesn't go far enough in either the
military/intelligence or commercial fields.
It is not uncommon for me to receive a document from comapny A under
nondisclosure agreemnt that can only be disclosed to certain people. Someone
else may receive a document from Company B that must be protected likewise.
Some people may be able to see proprietary documents from my own company, but
not company A or B. Others may see A, but not B, etc., etc. so "Company
Proprietary" must identify the company. This can be handled by a lattice model,
which is the way that compartmented clearances are handled.
Then you get into things like TOP SECRET NOFORN REL ANZAC, which means that the
document is top secret and cannot be released to anyone other than a US
citizen, except that it is releasable to Australia, New Zealand, and Canada.
and NODISSEM, which means that you can't give it to anybody without the
original author's approval.
In summary, this is a snakepit of problems, and outside of the scope of what
ought to be addressed within such a certificate. My advice would be to provide
a Classification field that is of type Textstring, and allowed to be of
arbitrary length (1024 is probably enough). Machine parsed access controls can
come later.
--------------------------------
Robert R. Jueneman
Mgr., Secure Systems
Wireless and Secure Systems Laboratory
GTE Laboratories
40 Sylvan Road
Waltham, MA 02254
Internet: Jueneman(_at_)gte(_dot_)com
FAX: 1-617-466-2603
Voice: 1-617-466-2820 (rolls over to cellular and/or my house
if no answer -- have patience)