PKIX Working Group                                      D. Pinkas (Bull)
INTERNET-DRAFT                                           T. Gindin (IBM)
Expires: November, 2000                                        May, 2000


                 Internet X.509 Public Key Infrastructure

                          Permanent Identifier

                       <draft-ietf-pkix-pi-00.txt>

Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of [RFC 2026].

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups. Note that other
   groups may also distribute working documents as Internet-Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time. It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   Copyright (C) The Internet Society (2000). All Rights Reserved.


Abstract

   This document define a new form of name, called permanent
   identifier, that may be included in the subjectAltName extension
   of a public key certificate issued to a physical person.

   The permanent identifier is an optional feature that may be used
   by a CA to indicate that the certificate relates to the same
   individual even if the name of that individual has changed.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119.

   Please send comments on this document to the ietf-pkix@imc.org
   mailing list.





Pinkas, Gindin                                               [ Page 1 ]


Permanent Identifier                 Document Expiration: November 2000

1  Introduction

   This specification is one part of a family of standards for the
   X.509 Public Key Infrastructure (PKI) for the Internet. It is based
   on RFC 2459, which defines underlying certificate formats and
   semantics needed for a full implementation of this standard.

   The subject field of a public key certificate identifies the entity
   associated with the public key stored in the subject public key
   field. The subject name may be carried in the subject field and/or
   the subjectAltName extension. Where it is non-empty, the subject
   field MUST contain an X.500 distinguished name (DN). The DN MUST be
   unique for each subject entity certified by the one CA as defined by
   the issuer name field.

   The subject name changes as soon as one of the components of that
   name gets changed. There are several reasons for this change to
   happen.

         For company's or organization's employees, the person may get
         a different position within the same company and thus will
         move from an organization unit to another one. Including the
         organisation unit in the name may however be very useful to
         allow the relying parties (RPs) using that certificate to
         identify the right individual.

         For citizens, an individual may change their name by legal
         processes, especially women as a result of marriage.

   A permanent identifier may be useful both in the context of access
   control and of non repudiation.

         For access control, the permanent identifier may be used in
         an ACL (Access Control List) instead of the DN or any other
         form of name and would not need to be changed, even if the
         subject name of the individual changes.

         For non-repudiation, the permanent identifier may be used to
         link different transactions to the same individual, even when
         the subject name of the individual changes.

   When two certificates from the same CA contain the same permanent
   identifier, then these certificates relate to the same individual.

2. Definition

   A permanent identifier is a name assigned by an organization,
   unique within that organization, that singles out a particular
   individual from all other individuals.  A CA which includes such
   an identifier in a certificate is certifying that any different
   public key certificate containing that identifier refers to the
   same individual.

Pinkas, Gindin                                               [ Page 2 ]


Permanent Identifier                 Document Expiration: November 2000

   The use of a permanent identifier is optional. This name is
   defined as a form of otherName from the GeneralName structure in
   SubjectAltName. The permanent identifier is defined as follows:

   id-on-permanentIdentifier   AttributeType ::= { id-on 2 }
   PermanentIdentifier ::=     SEQUENCE {
           assignerAuthority        GeneralName OPTIONAL,
           identifier               Name
   }

   The assignerAuthority field of this attribute, when present,
   identifies the name of the organization responsible for assigning
   the content of the identifier field. When the assignerAuthority
   field is missing, the assigner Authority is the CA itself and its
   name is assumed to be the issuer name of the certificate.

   The identifier field may contain any series of directory
   attributes. In particular, it may contain a serialNumber
   attribute. A serialNumber attribute may be used for two
   different purposes in the DN of a person:

         1) In a DN or a SubjectAltName to differentiate between
            two names (for two different individuals) that otherwise
            would not be different.

         2) In the identifier field from a permanent identifier.
            This is the recommended use for national ID's and
            employee ID's, for example.

Note: the full arc of the object identifier is derived using:

   id-pkix OBJECT IDENTIFIER ::= { iso(1) identified-organization(3)
   dod(6) internet(1) security(5) mechanisms(5) pkix(7) }

id-on   OBJECT IDENTIFIER ::= { id-pkix 8 }    -- other name forms

3. Security considerations

   A given individual may have at an instant of time or at different
   instants of time multiple forms of identities. When two
   certificates from the same CA contain two identical
   permanentIdentifiers in an otherName from a SubjectAltName, then a
   relying party may determine that the two certificates refer to the
   same individual.

4. References

   [RFC 2026] S. Bradner, "The Internet Standards Process -
   Revision 3 ¯,November 1996.

   [RFC 2119] S. Bradner, "Key words for use in RFCs to Indicate
   Requirement Levels", March 1997.



Pinkas, Gindin                                               [ Page 3 ]


Permanent Identifier                 Document Expiration: November 2000

   [RFC 2459] R. Housley, W. Ford, W. Polk, and D.Solo, "Internet X.509
   Public Key Infrastructure: Certificate and CRL Profile", January
   1999.

   [X.501]  ITU-T Recommendation X.501 (1997 E): Information Technology
   - Open Systems Interconnection - The Directory: Models, June 1997.

   [X.509]  ITU-T Recommendation X.509 (1997 E): Information Technology
   - Open Systems Interconnection - The Directory: Authentication
   Framework, June 1997.

   [X.520]  ITU-T Recommendation X.520: Information Technology - Open
   Systems Interconnection - The Directory: Selected Attribute Types,
   June 1997.

   [X.680]  ITU-T Recommendation X.680: Information Technology -
   Abstract Syntax Notation One, 1997.

5. Author's Addresses

   Denis Pinkas
   Bull S.A.
   12 rue de Paris
   B.P. 59
   78231 Le Pecq
   FRANCE
   Email: Denis.Pinkas@bull.net

   Thomas Gindin
   IBM Corporation
   6710 Rockledge Drive
   Bethesda, MD 20817
   USA
   Email: tgindin@us.ibm.com

6 Intellectual Property Rights

   The IETF takes no position regarding the validity or scope of any
   intellectual property or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; neither does it represent that it
   has made any effort to identify any such rights.  Information on the
   IETF's procedures with respect to rights in standards-track and
   standards related documentation can be found in BCP-11.  Copies of
   claims of rights made available for publication and any assurances of
   licenses to be made available, or the result of an attempt made to
   obtain a general license or permission for the use of such proprietary
   rights by implementors or users of this specification can be obtained
   from the IETF Secretariat.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights which may cover technology that may be required to practice

Pinkas, Gindin                                               [ Page 4 ]


Permanent Identifier                 Document Expiration: November 2000


   this standard.  Please address the information to the IETF Executive
   Director.


APPENDIX

ASN.1 definitions

A.1 1988 ASN.1  Module

PKIXpermanentidentifier88 {iso(1) identified-organization(3) dod(6)
       internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
       id-mod-permanent-identifier-88(14) }

DEFINITIONS EXPLICIT TAGS ::=

   BEGIN

   -- EXPORTS ALL --

   IMPORTS

        id-pkix, AttributeType, Name, GeneralName
                FROM PKIX1Explicit88 {iso(1) identified-organization(3)
                dod(6) internet(1) security(5) mechanisms(5) pkix(7)
                id-mod(0) id-pkix1-explicit-88(1)}
        GeneralName
                FROM PKIX1Implicit88 {iso(1) identified-organization(3)
                dod(6) internet(1) security(5) mechanisms(5) pkix(7)
                id-mod(0) id-pkix1-implicit-88(2)};

   -- Object Identifiers

-- Externally defined OIDs

   -- Arc for other name forms
   id-on   OBJECT IDENTIFIER ::= { id-pkix 8 }

   -- permanent identifier

   id-on-permanentIdentifier   AttributeType ::= { id-on 2 }

   PermanentIdentifier ::=     SEQUENCE {
           assignerAuthority        GeneralName OPTIONAL,
           identifier               Name
   }

END






Pinkas, Gindin                                               [ Page 5 ]


Permanent Identifier                 Document Expiration: November 2000


A.2 1993 ASN.1  Module

PKIXpermanentidentifier93 {iso(1) identified-organization(3) dod(6)
       internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
       id-mod-permanent-identifier-93(15) }

   DEFINITIONS EXPLICIT TAGS ::=

   BEGIN

   -- EXPORTS ALL --

   IMPORTS

GeneralName
       FROM PKIX1Implicit93 {iso(1) identified-organization(3) dod(6)
       internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
       id-pkix1-implicit-93(4)}

id-pkix, ATTRIBUTE, Name
       FROM PKIX1Explicit93 {iso(1) identified-organization(3) dod(6)
       internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
       id-pkix1-explicit-93(3)};

   -- Object Identifiers

-- Externally defined OIDs

   -- Arc for other name forms
   id-on   OBJECT IDENTIFIER ::= { id-pkix 8 }

-- Locally defined OIDs

id-on-permanentIdentifier     OBJECT IDENTIFIER ::= { id-on 2 }

   -- permanent identifier

permanentIdentifier ATTRIBUTE ::= {
       WITH SYNTAX     PermanentIdentifier,
       ID              id-on-permanentIdentifier }

PermanentIdentifier ::=     SEQUENCE {
           assignerAuthority       GeneralName OPTIONAL,
           identifier              Name
}


END






Pinkas, Gindin                                               [ Page 6 ]


Permanent Identifier                 Document Expiration: November 2000


E.  Full Copyright Statement

   Copyright (C) The Internet Society (2000). All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  In addition, the
   ASN.1 modules presented in Appendices A and B may be used in whole or
   in part without inclusion of the copyright notice.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process shall be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns. This
   document and the information contained herein is provided on an "AS
   IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK
   FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT
   LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL
   NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY
   OR FITNESS FOR A PARTICULAR PURPOSE.


























Pinkas, Gindin                                               [ Page 7 ]