GLobal Unique Enterprise (GLUE) Identifiers
draft-ietf-spice-glue-id-05

Secure Patterns for Internet CrEdentials                    B. W. Zundel
Internet-Draft                                                          
Intended status: Standards Track                               P. Dingle
Expires: 20 August 2026                            Microsoft Corporation
                                                             M. B. Jones
                                                  Self-Issued Consulting
                                                        16 February 2026

              GLobal Unique Enterprise (GLUE) Identifiers
                      draft-ietf-spice-glue-id-05

Abstract

   This specification establishes a URN namespace for GLobal Unique
   Enterprise (GLUE) Identifiers.  This enables URN identifiers to be
   used for businesses and organizations.  It enables organizational
   identities from existing authorities to be represented within this
   URN namespace.

About This Document

   This note is to be removed before publishing as an RFC.

   The latest revision of this draft can be found at https://ietf-wg-
   spice.github.io/draft-ietf-spice-glue-id/draft-ietf-spice-glue-
   id.html.  Status information for this document may be found at
   https://datatracker.ietf.org/doc/draft-ietf-spice-glue-id/.

   Discussion of this document takes place on the Secure Patterns for
   Internet CrEdentials Working Group mailing list
   (mailto:[email protected]), which is archived at
   https://mailarchive.ietf.org/arch/browse/spice/.  Subscribe at
   https://www.ietf.org/mailman/listinfo/spice/.

   Source for this draft and an issue tracker can be found at
   https://github.com/ietf-wg-spice/draft-ietf-spice-glue-id.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
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   Internet-Drafts are draft documents valid for a maximum of six months
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Requirements Notation and Conventions . . . . . . . . . .   3
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Core Concepts . . . . . . . . . . . . . . . . . . . . . . . .   4
     2.1.  Uniqueness and Namespacing  . . . . . . . . . . . . . . .   4
   3.  GLUE URIs . . . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  GLUE Authority Identifiers  . . . . . . . . . . . . . . . . .   6
     4.1.  Equivalence to Similar URIs . . . . . . . . . . . . . . .   6
       4.1.1.  LEI URNs  . . . . . . . . . . . . . . . . . . . . . .   7
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   6.  Privacy Considerations  . . . . . . . . . . . . . . . . . . .   7
     6.1.  Private Identifiers as Corporate Identifiers  . . . . . .   7
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
     7.1.  GLUE Authority Identifier URN Registry  . . . . . . . . .   9
       7.1.1.  Registration Template . . . . . . . . . . . . . . . .   9
       7.1.2.  Initial Registry Contents . . . . . . . . . . . . . .  10
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  11
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  12
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  12
   Document History  . . . . . . . . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

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1.  Introduction

   There are myriad entity identifier types for businesses and
   organizations.  With the increasing use of digital credentials, there
   is a need for a common methodology for expressing these identifiers
   such that claims about and by such entities can be made in a
   consistent and interoperable manner.

   This specification establishes a URN namespace that standardizes the
   expression of existing organizational entity identifiers by providing
   a common representation format.  It also establishes a registry for
   managing how existing organizational entity identification mechanisms
   relate to this namespace.

   Any organizational entity identifier whose identification mechanism
   has been registered as an Authority Identifier in the registry may be
   represented as a GLUE URI.

1.1.  Requirements Notation and Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

1.2.  Terminology

   This specification uses the following terms:

   GLUE URI:  a URI that uses the GLUE URN namespace established in this
      specification.

   External Authority:  an organization that allocates External
      Identifiers for GLUE URIs using the Authority Identifier(s) over
      which they have jurisdiction.

   Authority Identifier:  identifier for the External Authority
      responsible for assigning the External Identifier used in GLUE
      URIs.

   External Identifier:  identifier assigned by an External Authority to
      identify a particular organization within GLUE URNs over which it
      has jurisdiction.

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2.  Core Concepts

   Every GLUE URI MUST contain the following components:

   *  The Authority Identifier

   *  The External Identifier

2.1.  Uniqueness and Namespacing

   Each GLUE URI MUST be globally unique.

   A business entity can be identified by multiple GLUE URIs, but each
   GLUE URI can only refer to a single business entity.

   It is assumed that most registered organizational entity
   identification schemes already handle any necessary namespacing as
   part of the External Identifier.  However, if collisions are possible
   within the set of possible external identifiers for an Authority
   Identifier scheme, then further namespacing is necessary at the GLUE
   URI level.  Such namespacing MUST be done on the Authority
   Identifier.  The combination of the namespacing and the authority
   MUST result in a unique Authority Identifier.

   For example, assume there is an External Authority FEA that provides
   identifiers for organizations in Singapore and South Korea.  The
   identifiers issued in Singapore are unique within Singapore, and the
   identifiers issued in South Korea are unique within South Korea, but
   there is no guarantee that an organization in Singapore will not be
   assigned the same identifier as an organization in South Korea.  Upon
   registration of FEA as an Authority Identifier, it would be necessary
   to separately register two different Authority Identifiers (e.g.,
   FEA-SG and FEA-KR) to provide differentiation between the two sets of
   External Identifiers.

3.  GLUE URIs

   GLUE URIs comply with [RFC3986].  They begin with urn:glue: and are
   followed by an Authority Identifier, a colon character (":"), and the
   External Identifier allocated by the authority.

   Authority Identifiers consist of a sequence of characters beginning
   with a letter or digit and followed by any combination of letters,
   digits, plus ("+"), hyphen ("-"), or period (".").  Although
   Authority Identifiers are case-insensitive, the canonical form is
   lowercase and documents that specify Authority Identifiers must do so
   with lowercase letters.  An implementation should accept uppercase
   letters as equivalent to lowercase in Authority Identifier names

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   (e.g., allow "EXAMPLE" as well as "example") for the sake of
   robustness but should only produce lowercase Authority Identifier
   names for consistency.  There is a limit of 50 characters for the
   length of an Authority Identifier.  The ABNF [RFC5234] for Authority
   Identifiers is:

   authority-identifier = (ALPHA/DIGIT) *49( ALPHA / DIGIT / "+" / "-" /
   "." )

   External Identifiers consist of a sequence of characters beginning
   with a letter or digit or hyphen ("-") and followed by any
   combination of letters, digits, plus ("+"), hyphen ("-"), or period
   (".").  A digit or hyphen is allowed as the first character to permit
   the case where the External Identifier is the representation of a
   number.  It is specific to the Authority Identifier whether the
   External Identifiers are case-insensitive or case-sensitive.  When
   they are case-insensitive, the canonical form is lowercase and
   documents that specify External Identifiers must do so with lowercase
   letters.  There is a limit of 1000 characters for an External
   Identifier.  The ABNF [RFC5234] for External Identifiers is:

   external-identifier = ( ALPHA / DIGIT / "-" ) *999( ALPHA / DIGIT /
   "+" / "-" / "." )

   Combining these, the ABNF [RFC5234] for a GLUE URI is:

   glue-uri = "urn:glue:" authority-identifier ":" external-identifier

   For example, the following is a GLUE URI using the Authority
   Identifier "pen" and the External Identifier "32473":

   urn:glue:pen:32473

   A GLUE URI is defined over the restricted US-ASCII syntax specified
   in this section.  Percent-encoding is not permitted.  Consequently,
   GLUE URIs do not support representation of External Identifiers whose
   canonical form includes non-ASCII characters.  This specification is
   therefore limited to identifier systems whose canonical
   representations are fully within the permitted character set.

   The Authority Identifier MUST be registered in the GLUE URI Authority
   Identifier registry defined in Section 7.1.  The External Identifier
   MUST be the identifier assigned to the organization by the External
   Authority.

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4.  GLUE Authority Identifiers

   This section defines the following GLUE Authority Identifiers.

     +==============+============+===================================+
     | Organization | Authority  | External Authority Specification  |
     |              | Identifier |                                   |
     +==============+============+===================================+
     | GS1          | gln        | https://www.gs1.org/standards/id- |
     |              |            | keys/gln                          |
     +--------------+------------+-----------------------------------+
     | GLEIF        | lei        | https://www.iso.org/              |
     |              |            | standard/78829.html               |
     +--------------+------------+-----------------------------------+
     | Dun &        | duns       | https://www.dnb.com/duns.html     |
     | Bradstreet   |            |                                   |
     +--------------+------------+-----------------------------------+
     | Private      | pen        | https://www.iana.org/assignments/ |
     | Enterprise   |            | enterprise-numbers                |
     | Numbers      |            |                                   |
     +--------------+------------+-----------------------------------+
     | ISO/IEC 6523 | iso6523    | https://www.iso.org/              |
     |              |            | standard/82246.html               |
     +--------------+------------+-----------------------------------+

                                  Table 1

   They are registered in the GLUE Authority Identifier URN Registry in
   Section 7.1.

4.1.  Equivalence to Similar URIs

   A GLUE URI is an identifier in a distinct URN namespace.  By default,
   a GLUE URI is not equivalent to any other URI, including a URI
   defined by the referenced authority's own namespace.  Equivalence
   between a GLUE URI and a non-GLUE URI exists only when explicitly
   specified for a given Authority Identifier.  Implementations and
   relying parties MUST NOT assume equivalence between GLUE URIs and
   non-GLUE URIs unless such equivalence is explicitly defined by the
   authority or documented in the relevant registry entry.

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4.1.1.  LEI URNs

   [LEI-IANA] registers a URN namespace for LEIs.  This means that LEIs
   can be represented as URNs in at least two ways.  Therefore there is
   an equivalence between a GLUE URI with an "lei" Authority Identifier
   and an LEI URN, provided the 20-digit LEI Code of the LEI URN is
   identifical to the External Identifier of the GLUE URI.  For example,
   "urn:lei:INR2EJN1ERAN0W5ZP974" is equivalent to
   "urn:glue:lei:INR2EJN1ERAN0W5ZP974".

5.  Security Considerations

   There are no additional security considerations beyond those already
   inherent to using URNs.  Security considerations for URNs can be
   found in [RFC2141].

6.  Privacy Considerations

6.1.  Private Identifiers as Corporate Identifiers

   There are some corporate identifiers that make use of personal
   identifiers.  For example, this is the case for some registered sole-
   proprietor businesses in the United States, where the Tax ID may be
   the same as the Social Security Number (SSN) of the business owner.
   Where the Tax ID uniquely identifies the business, the SSN uniquely
   identifies an individual.

   It is possible for such business identifiers to be represented as
   GLUE URIs.  An identifier's expression as a GLUE URI does not change
   the privacy characteristics of that identifier.  The same cautions
   and concerns need to be taken with the GLUE URI representation as
   with the original identifier.

   Implementers storing or evaluating GLUE URIs are encouraged to be
   aware the privacy characteristics of each identification scheme
   represented by an Authority Identifier and to appropriately handle
   any GLUE URI which violates privacy policies.

7.  IANA Considerations

   This section establishes a registry and populates it with its initial
   contents.

   Values are registered on a Specification Required [RFC8126] basis
   after a two-week review period on the [email protected]
   mailing list, on the advice of one or more Designated Experts.
   However, to allow for the allocation of values prior to publication
   of the final version of a specification, the Designated Experts may

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   approve registration once they are satisfied that the specification
   will be completed and published.  However, if the specification is
   not completed and published in a timely manner, as determined by the
   Designated Experts, the Designated Experts may request that IANA
   withdraw the registration.

   Registration requests sent to the mailing list for review should use
   an appropriate subject (e.g., "Request to register URN
   urn:glue:example").

   Within the review period, the Designated Experts will either approve
   or deny the registration request, communicating this decision to the
   review list and IANA.  The Designated Experts verify that a
   specification exists.  Experts are encouraged to be biased towards
   approving registrations unless they are abusive, frivolous, or
   actively harmful (not merely aesthetically displeasing or
   architecturally dubious).

   Denials should include an explanation and, if applicable, suggestions
   as to how to make the request successful.  If the designated experts
   are not responsive, the registration requesters should contact IANA
   to escalate the process.

   Criteria that should be applied by the Designated Experts includes
   determining whether the proposed registration duplicates existing
   functionality, determining whether it is likely to be of general
   applicability or whether it is useful only for a single application,
   and whether the registration makes sense.

   IANA must only accept registry updates from the Designated Experts
   and should direct all requests for registration to the review mailing
   list.

   It is suggested that multiple Designated Experts be appointed who are
   able to represent the perspectives of different applications using
   this specification, in order to enable broadly-informed review of
   registration decisions.  In cases where a registration decision could
   be perceived as creating a conflict of interest for a particular
   Expert, that Expert should defer to the judgment of the other
   Experts.

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   The reason for the use of the mailing list is to enable public review
   of registration requests, enabling both Designated Experts and other
   interested parties to provide feedback on proposed registrations.
   The reason to allow the Designated Experts to allocate values prior
   to publication as a final specification is to enable giving authors
   of specifications proposing registrations the benefit of review by
   the Designated Experts before the specification is completely done,
   so that if problems are identified, the authors can iterate and fix
   them before publication of the final specification.

7.1.  GLUE Authority Identifier URN Registry

   This specification establishes the IANA "GLUE Authority Identifier
   URN" registry creating a URN namespace for Authority Identifiers for
   GLobal Unique Enterprise (GLUE) Identifiers.

   Each entry registers the URN for an Authority Identifier within the
   "urn:glue:" namespace.  The organization responsible for the
   Authority Identifier is recorded.

   IANA is requested to create the "GLobal Unique Enterprise (GLUE)
   Identifiers" registry group located at
   https://www.iana.org/assignments/glue-identifiers/ and place this
   registry there.

7.1.1.  Registration Template

   Authority Identifier:  identifier for the External Authority
      responsible for assigning the External Identifier used in GLUE
      URIs.  This identifier is not case sensitive and any letters MUST
      be expressed in lowercase characters.  It MUST consist of a
      sequence of characters with a mazimum length of 50, beginning with
      a letter and followed by any combination of letters, digits, plus
      ("+"), period ("."), or hyphen ("-").

   URN:  The URN within the "urn:glue:" namespace consisting of
      "urn:glue:" followed by the Authority Identifier.

   Organization:  The organization responsible for the Authority
      Identifier.

   Change Controller:  For IETF stream RFCs, use "IETF".  For others,
      give the name of the responsible party.  Other details (e.g.,
      postal address, e-mail address, home page URI) may also be
      included.

   Specification Document(s):  Reference to the document or documents

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      that specify the Authority Identifier to be registered, preferably
      including URLs that can be used to retrieve the documents.  An
      indication of the relevant sections may also be included, but is
      not required.

7.1.2.  Initial Registry Contents

7.1.2.1.  gln

   *  Authority Identifier: gln

   *  URN: urn:glue:gln

   *  Organization: GS1

   *  Change Controller: IETF

   *  Specification Document(s): Section 4 of this specification, [GLN]

7.1.2.2.  lei

   *  Authority Identifier: lei

   *  URN: urn:glue:lei

   *  Organization: GLEIF

   *  Change Controller: IETF

   *  Specification Document(s): Section 4 of this specification, [LEI],
      [LEI-IANA]

7.1.2.3.  duns

   *  Authority Identifier: duns

   *  URN: urn:glue:duns

   *  Organization: Dun & Bradstreet

   *  Change Controller: IETF

   *  Specification Document(s): Section 4 of this specification, [DUNS]

7.1.2.4.  pen

   *  Authority Identifier: pen

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   *  URN: urn:glue:pen

   *  Organization: Private Enterprise Numbers

   *  Change Controller: IETF

   *  Specification Document(s): Section 4 of this specification, [PEN],
      [RFC9371]

7.1.2.5.  iso6523

   *  Authority Identifier: iso6523

   *  URN: urn:glue:iso6523

   *  Organization: ISO/IEC 6523

   *  Change Controller: IETF

   *  Specification Document(s): Section 4 of this specification,
      [ISO6523]

8.  References

8.1.  Normative References

   [DUNS]     "D-U-N-S Numbers", n.d., <https://www.dnb.com/duns.html>.

   [GLN]      "Global Location Nymber (GLN)", n.d.,
              <https://www.gs1.org/standards/id-keys/gln>.

   [ISO6523]  "ISO/IEC 6523-1:2023. Information technology — Structure
              for the identification of organizations and organization
              parts, Part 1: Identification of organization
              identification schemes", 2023,
              <https://www.iso.org/standard/82246.html>.

   [LEI]      "Legal Entity Identifier (LEI)", 2020,
              <https://www.iso.org/standard/78829.html>.

   [LEI-IANA] "LEI Namespace Identifier", n.d.,
              <https://www.iana.org/assignments/urn-formal/lei>.

   [PEN]      "Private Enterprise Numbers", n.d.,
              <https://www.iana.org/assignments/enterprise-numbers>.

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   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/rfc/rfc2119>.

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, DOI 10.17487/RFC3986, January 2005,
              <https://www.rfc-editor.org/rfc/rfc3986>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.

8.2.  Informative References

   [RFC2141]  Moats, R., "URN Syntax", RFC 2141, DOI 10.17487/RFC2141,
              May 1997, <https://www.rfc-editor.org/rfc/rfc2141>.

   [RFC5234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", STD 68, RFC 5234,
              DOI 10.17487/RFC5234, January 2008,
              <https://www.rfc-editor.org/rfc/rfc5234>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/rfc/rfc8126>.

   [RFC9371]  Baber, A. and P. Hoffman, "Registration Procedures for
              Private Enterprise Numbers (PENs)", RFC 9371,
              DOI 10.17487/RFC9371, March 2023,
              <https://www.rfc-editor.org/rfc/rfc9371>.

Acknowledgments

   Carsten Bormann, Tim Bray, Patrik Fältström, Arnt Gulbrandsen, Sue
   Hares, John Klensin, Martin Lindström, Rohan Mahy, James Manger, Orie
   Steele, Alexander (A.J.)  Stein, Martin Thomson, and Peter Yee
   contributed to this specification.

Document History

   -05

   *  Added ISO/IEC 6523 identifiers.

   *  The first character of the Authority Identifier may be a digit.

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   *  Fixed wording in IANA Considerations.

   *  Limited character set to US-ASCII.

   *  Fixed multiple nits from WGLC.

   -04

   *  Applied review suggestions from Martin Thomson, specifically:

      -  Added references for each registered Authority Identifier.

      -  Added size limits for Authority Identifiers and External
         Identifiers.

      -  Added a note about LEI URNs.

   -03

   *  Use the urn:glue URN namespace and delete the urn:ietf:spice URN
      namespace.

   *  Addressed early IANA feedback.

   -02

   *  Improved several descriptions in the specification.

   -01

   *  Updated Brent's affiliation.

   -00

   *  Initial working group draft, based on draft-zundel-spice-glue-
      id-02

Authors' Addresses

   Brent W. Zundel
   United States
   Email: [email protected]

   Pamela Dingle
   Microsoft Corporation
   United States
   Email: [email protected]

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   Michael B. Jones
   Self-Issued Consulting
   United States
   Email: [email protected]
   URI:   https://self-issued.info/

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