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Proposed changes to the UNTP DIA Spec

1. Summary

This proposal requests an extension to the current UNTP Digital Identity Anchor (DIA) specification to support the inclusion of supplementary identifiers (e.g., GS1, LEI, ISO) within a single verifiable credential. Crucially, it introduces a trustLevel attribute to allow Authoritative Registrars to distinguish between identifiers they have verified and those that are merely asserted by the subject.

2. Problem Statement

The current DIA specification defines a single identifier value for a legal entity. The GTR project review recognises this identifier value as the one that is issued by the Authoritative Registrar for the registry and for the registration of that entity in their register. However, in global trade, an entity is often recognized by multiple identifiers across different jurisdictions and supply chain standards (e.g., a National Business ID, a GS1 GLN, and an LEI).

Providing an option to encapsulate these "Supplementary Identifiers" within the DIA increases the value of the credential and can mitigate potential problems:

  1. Identifier Siloing: Verifiers must collect and verify multiple separate credentials, potentially increasing trade friction.

  2. Liability Risk: Authoritative Registrars are hesitant to include third-party identifiers (like GS1) in a signed DIA because, under current specs, there is no way to signal that they are not the authoritative source for that specific ID.

  3. Lack of Discovery: There is no explicit link between the DIA and a global trust root (like the GRID) for automated registrar key discovery.

3. Proposed Solution

We propose adding an optional supplementaryIdentifiers array and a registrar metadata block to the credentialSubject.

3.1 Trust Attribution Model

Each supplementary identifier is assigned a trustLevel flag:

  • Verified: The Registrar has proactively cross-checked this third-party ID against its own authoritative records.

  • Asserted: The ID is provided by the entity. The Registrar conveys it for trade convenience but assumes zero liability for its accuracy.

3.2 Metadata Discovery

Adding a gridReference within the registrar block allows verifiers to automatically resolve the Registrar’s public key and legal status via the Global Trust Registry (GRID).

4. Technical Specification (JSON-LD)

Target Object: credentialSubject

{
  "identifier": "123456789", 
  "scheme": "NationalBusinessRegistry_AU",
  "registrar": {
    "name": "ASIC",
    "gridReference": "https://gtr.un.org/registrars/au-asic"
  },
  "supplementaryIdentifiers": [
    {
      "identifier": "549300863866281234",
      "scheme": "vLEI",
      "trustLevel": "Verified" 
    },
    {
      "identifier": "9312345678901",
      "scheme": "GS1_GLN",
      "trustLevel": "Asserted" 
    }
  ]
}

5. Rationale & Use Cases

  • Use Case - Customs Clearance: A business presents a DIA at a border. The Customs officer sees the National ID (Authoritative) but also the GS1 GLN (Verified), allowing them to instantly link the legal entity to the physical goods in the shipping manifest.

  • Use Case - Financial KYC: A bank receives a DIA and sees an LEI marked as Asserted. The bank knows they must perform their own due diligence on the LEI, whereas if it were marked Verified, they could rely on the Registrar’s prior check.

6. Compatibility & Impact

  • Backward Compatibility: This is a non-breaking extension. The root identifier and scheme remain unchanged.

  • Alignment: This aligns the UNTP with the UNCITRAL Model Law on Identity Management (MLIT) by providing clear attribution for trust services.

Suggested Submission Note:

"This issue is submitted by the UN/CEFACT GTR Project Co-Leads following a strategic review of sovereign registrar requirements for global trade. The proposed 'Trust Attribution Model' is essential for securing the participation of national registries by providing a clear legal 'liability shield' for third-party identifiers."

Edited by John Phillips