Attestation Rulebook for attestations of type DUNS

Category: non-qualified EAA

• Author(s):

  • [Werner Folkendt, Robert Bosch GmbH]

• Reviewer(s):

  • [Dominic Hurni, SBB]
  • [Florin Coptil, Robert Bosch GmbH]

• Contact:

  • Werner Folkendt *

Written against: ARF version 3.0.0, WE BUILD template version 1.0 (generic)

Feedback: GitHub issues

Table of contents

• 1 Introduction
  • 1.1 Document scope and purpose
  • 1.2 Document structure
  • 1.3 Key words
  • 1.4 Terminology
• 2 Compliance
  • 2.1 Compliance statement
  • 2.2 Regulatory basis
  • 2.3 Traceability
• 3 Attestation attributes
  • 3.1 Introduction
  • 3.2 Mandatory attributes
  • 3.3 Optional attributes
  • 3.4 Conditional attributes
• 4 Metadata
  • 4.1 Mandatory metadata
  • 4.2 Optional metadata
  • 4.3 Conditional metadata
  • 4.4 Code lists
  • 4.5 Integrity rules
• 5 Formats
  • 5.1 SD-JWT VC-based encoding
  • 5.2 ISO/IEC 18013-5-compliant encoding
  • 5.3 W3C Verifiable Credentials Data Model-based encoding
• 6 Protocols
• 7 Issuance
  • 7.1 Binding
  • 7.2 Issuance Policy
  • 7.3 Lifecycle management
  • 7.4 Embedded disclosure policy
• 8 Revocation
• 9 Presentation
  • 9.1 Presentation Policy
  • 9.2 Presentation modes
  • 9.3 Transactional data
• 10 Trust Framework
• 11 References

1 Introduction

A DUNS Legal Entity Attestation contains the DUNS number (DUNS – Data Universal Numbering System) provided by Dun & Bradstreet to a legal entity and additional legal entity name and adress information. A DUNS number is a unique identifier issued by Dun & Bradstreet for three types of business entities: a) legal entities b) sites and c) locations.

The DUNS number is a nine-digit numeric code that uniquely identifies a business entity worldwide, providing a standardized reference for suppliers, customers, and regulatory authorities.

In the context of supplier verification and the Know Your Supplier (KYS) process, a DUNS number serves several critical functions. In several industry branches it is impossible for a legal entity to do business without providing this number to business partners.

1.1 Document scope and purpose

The DUNS Legal Entity Attestation complements the EUCC by providing the DUNS number for a legal entity. With this number an EBW owner can acces the Dun & Bradstreet Database to request additional non-core identity attributes required for KYS, KYC, supplier onboarding, and risk assessment processes.

1.2 Document structure

This Rulebook follows the generic WE BUILD attestation rulebook template. Chapter 2 states how it complies with the ARF and the applicable Regulations. Chapters 3 and 4 define the attributes and metadata in an encoding-independent manner. Chapter 5 states the formats in which this attestation is issued. Chapters 6 to 9 cover protocols, issuance, revocation and presentation. Chapter 10 sets out the trust framework, and chapter 11 lists references.

1.3 Key words

This document uses the capitalised key words 'SHALL', 'SHOULD' and 'MAY' as specified in [RFC 2119], to indicate requirements, recommendations and options.

In addition, 'must' (non-capitalised) indicates an external constraint, a requirement not mandated by this document but by an external document. The word 'can' indicates a capability. Other words such as 'will', 'is' and 'are' are statements of fact.

1.4 Terminology

Additional terminology specific to this attestation:

2 Compliance

2.1 Compliance statement

This Rulebook complies with the applicable requirements of Topic 12, Attestation Rulebooks, in Annex 2 of the Architecture and Reference Framework, version 3.0.0. It uses the terminology of Annex 1 of the ARF.

2.2 Regulatory basis

This attestation is not a qualified electronic attestation of attributes. The data described in Annex V points b, c and e of Regulation (EU) 2024/1183 is addressed as required by EW-DM-12-018 and as recommended by EW-DM-12-020 and EW-DM-12-022. Where a recommendation is not followed, the reason is stated below.

2.3 Traceability

Every applicable requirement mapped to the section that satisfies it. Requirements marked not applicable carry a stated reason.

3 Attestation attributes

Attributes are defined here in an encoding-independent manner (EW-DM-12-007). The encoding of each attribute is given in chapter 5.

3.1 Introduction

The DUNS Legal Entity Attestation provides a standardized, verifiable representation of a legal entity DUNS number, name, legal form and main adress information.

Data Model:

The attestation structure is defined as a structured object with a nested array of financial facts:

DUNS
├─ duns_number (tstr)
├─ legal_entity (Object)
│   ├─ legal_name (tstr)
│   └─ legal_form (tstr)
│   └─ address (Address)
│       ├─ [street]
│       ├─ [nr]
│       ├─ [postal_code]
│       ├─ [city]
│       └─ [country]

Note: M - mandatory / O - optional.

Explanation:

• duns_number is the mandatory nine-digit unique identifier assigned by Dun & Bradstreet to the legal entity.
• legal_entity is a mandatory object encapsulating the legal identity of the entity, containing:
  • legal_name: the registered legal name of the entity (mandatory).
  • legal_form: the legal form of the entity (e.g., GmbH, AG, Ltd.) (mandatory).
  • registered_address: the official registered address of the entity (mandatory object), with all address sub-fields being optional:
    • street: street name of the registered address.
    • nr: street or building number.
    • postal_code: postal or ZIP code.
    • city: city or municipality.
    • country: country of the registered address (ISO 3166-1 alpha-2).

Attestation Classification:

This attestation type MAY be classified as:

• "EAA" self-issued by the legal entity as part of its disclosures or authorized competent body that can independently attest the company information (e.g., based on official Dun & Bradstreet registry data).

VC Type: vct: eu.we-build:duns:1

3.2 Mandatory attributes

DUNS Attestation Attributes

Nested Mandatory Attributes

3.3 Optional attributes

Address Optional Attributes The following sub-fields within the legal_entity.address object are optional.

3.4 Conditional attributes

No conditional attributes are defined for this attestation type.

4 Metadata

Metadata describes the attestation rather than its subject.

4.1 Mandatory metadata

Note: Standard JWT claims (iss, iat, exp) are also mandatory.

Legal category. This Rulebook retains the attestation_legal_category attribute. Section 4.1 of the generic template replaces it with the category attribute of [ETSI TS 119 472-1], whose value for this category is eaa:eu:non-qualified. EW-DM-12-029, legacy ARB_25, of ARF version 3.0.0 is a SHALL that still requires attestation_legal_category, so the template and the ARF disagree. The attribute is left as written and the deviation is recorded for the rulebook quality assurance group.

4.2 Optional metadata

4.3 Conditional metadata

No conditional metadata elements are defined for this attestation type.

4.4 Code lists

4.4.1 Country Codes

The legal_entity.address.country attribute, if provided, SHALL use a country code as defined by ISO 3166-1 alpha-2 (e.g., DE for Germany, US for United States).

4.5 Integrity rules

The following integrity rules SHALL be enforced:

• duns_number SHALL be a non-empty nine-digit numeric string.
• The legal_entity object SHALL be present.
• legal_entity.legal_name and legal_entity.legal_form SHALL be non-empty strings.
• The legal_entity.address object SHALL be present.
• legal_entity.address.country, if provided, SHALL conform to ISO 3166-1 alpha-2.

5 Formats

5.1 SD-JWT VC-based encoding

The DUNS Legal Entity attestation uses the SD-JWT VC format to allow for selective disclosure.

Verifiable Credential Type (vct): eu.we-build:duns:1

5.1.1 Attribute Encoding Table

5.1.2 Status Claim

For SD-JWT VC-compliant Attestations, the attestation MUST include a status claim if the technical validity period is greater than 24 hours.

The status claim SHALL be a JSON object with the following members:

Example:

{
  "status": {
    "type": "status-list",
    "status_list_credential": "https://issuer.example.com/status/duns/2025",
    "status_list_index": 456,
    "status_purpose": "revocation"
  }
}

5.1.3 Example Payload

The following is a non-normative example of a DUNS SD-JWT VC payload:

{
  "vct": "eu.we-build:duns:1",
  "iss": "did:example:duns-issuer-001",
  "iat": 1736935200,
  "exp": 1768471200,
  "attestation_legal_category": "EAA",
  "duns_number": "123456789",
  "legal_entity": {
    "legal_name": "Example GmbH",
    "legal_form": "GmbH",
    "address": {
      "street": "Musterstraße",
      "nr": "42",
      "postal_code": "70174",
      "city": "Stuttgart",
      "country": "DE"
    }
  },
  "status": {
    "type": "status-list",
    "status_list_credential": "https://issuer.example.com/status/duns/2025",
    "status_list_index": 456,
    "status_purpose": "revocation"
  },
  "cnf": {
    "jwk": {
      "kty": "EC",
      "crv": "P-256",
      "x": "TCAER19Zvu3OHF4j4W4vfSVoHIP1ILilDls7vCeGemc",
      "y": "ZxjiWWbZMQGHVWKVQ4hbSIirsVfuecCE6t4jT9F2HZQ"
    }
  }
}

Sample payloads are provided under ../data-schemas/sd-jwt/sample-data/duns-sd-jwt-sample.json

5.2 ISO/IEC 18013-5-compliant encoding

ISO/IEC 18013-5 is out of scope for this Rulebook.

5.3 W3C Verifiable Credentials Data Model-based encoding

This Rulebook does not define a W3C Verifiable Credentials Data Model encoding for this attestation type.

6 Protocols

This attestation is issued using OpenID for Verifiable Credential Issuance [OpenID4VCI] and presented using OpenID for Verifiable Presentations [OpenID4VP], both as profiled by [HAIP].

7 Issuance

7.1 Binding

7.2 Issuance Policy

For EAA (Self-Issued / Standard Issuance):

• The issuer (i.e., the legal entity itself) issues the attestation based on the information and supporting documentation available at the time of issuance.
• The issuer is responsible for ensuring that the attested information remains accurate and must immediately revoke the attestation if any change occurs that affects the validity or accuracy of the underlying data.

The Issuer SHALL implement the base issuer obligation as defined in the Issuer Obligation specification: https://github.com/webuild-consortium/webuild-attestation-rulebooks-catalog/blob/main/rulebooks/rb-base/verifier-base-verification.md#41-issuer-obligations

7.3 Lifecycle management

The issuer sets the validity period of the attestation and reissues it when the underlying facts change, revoking the superseded attestation as described in chapter 8.

7.4 Embedded disclosure policy

This attestation defines no embedded disclosure policy.

8 Revocation

An attestation SHALL remain valid only while its underlying information is accurate, complete, and legally effective.

8.1 Revocation Mechanism

• Token Status List: The issuer must maintain an active IETF Token Status List (aligned with the Attestation Status List mechanism specified by the EU Commission).
• Credential Metadata: The metadata status_list must be populated in every issued CompanyInfo attestation, referencing the status list URI and the credential's specific index.

Authorized Authority: Only the authorized issuer (the QTSP/competent body for QEAA, or the self-issuing legal entity for EAA) may modify the status list entry.

8.2 Revocation Triggers & Business Rules

• EAA Trigger (Manual Obligation): The self-issuing legal entity is under strict obligation to immediately update or revoke its EAA if its available documents, financial thresholds, or ownership structures change.

Relying Party Action: A revoked or suspended attestation must be treated as invalid for credential-validity purposes by all RPs. The business interpretation is determined by the Relying Party's internal compliance policies.

9 Presentation

Base Verification Process

The Relying Party SHALL perform the base attestation verification process as defined in the Base Verification specification: https://github.com/webuild-consortium/webuild-attestation-rulebooks-catalog/blob/main/rulebooks/rb-base/verifier-base-verification.md#42-relying-party-obligations

9.1 Presentation Policy

To verify and validate a received presentation of an attestation of this type, the following steps SHALL be performed:

1. verify the signature over the attestation using a trust anchor obtained as described in chapter 10;
2. verify that the attestation is within its validity period;
3. check revocation status as described in chapter 8, unless the attestation is short-lived, or its remaining lifetime is below the revocation time threshold;
4. verify device binding where section 7.1 records the attestation as device-bound;
5. request only those attributes that are necessary for the stated purpose of the transaction, and, where the trust model for this attestation requires Relying Party registration, only those attributes it is registered and authorised to request.

Obligations specific to this attestation type, carried over from the previous version of this Rulebook:

When receiving and processing an attestation, the Relying Party SHALL perform the following verification obligations.

9.2 Presentation modes

Remote presentation is in scope. Proximity presentation is in scope only where chapter 5 records an mdoc encoding.

9.3 Transactional data

This Rulebook defines no transactional data.

10 Trust Framework

This chapter specifies the trust anchor mechanisms used by Relying Parties to establish trust in the issuer of an Electronic Attestation of Attributes (EAA) . The corresponding verification procedures are defined in Sections 4.2.2–4.2.4.

10.1 Qualified Electronic Attestations of Attributes (QEAAs)

not available.

10.2 Electronic Attestations of Attributes (EAAs)

For EAAs, trust is established through a cryptographic chain anchored in the Electronic Business Wallet Owner Identity Document (EBWOID). The EBWOID SHALL be included in the header of every EAA. During EBWOID issuance, the EBWOID provider verifies that the public key contained in the EBWOID is owned by the Electronic Business Wallet (EBW) owner.

The Relying Party SHALL verify the EBWOID in accordance with the verification procedure defined in this Rulebook. Upon successful verification, the Relying Party obtains:

• assurance that the EBWOID was issued by an authorized provider and is not self-issued;
• the verified identity of the issuer, including its name and EUID (or another globally unique EBW owner identifier); and
• the public key authorized to verify the EAA signature.

Authorization of the issuer is subsequently determined in accordance with the Relying Party's internal policies. Such authorization MAY be based on locally maintained wallet configuration or on trusted jurisdiction- or domain-specific trust list services that identify issuers authorized for a particular type of EAA

Trust anchor location

The attribute or metadata carrying the trust anchor location contains at least the URL at which a machine-readable version can be found or looked up.

11 References