Attestation Rulebook for attestations of type Site

Category: non-qualified EAA

• Author(s):
  • [Dominic Hurni, SBB]
  • [Werner Folkendt, Robert Bosch GmbH]
• Reviewer(s):
  • [Florin Coptil, Robert Bosch GmbH]
• Contact:
  • Dominic Hurni *
  • Werner Folkendt *
• Sources:
  • Powerpoint
  • Excel

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
  • 6.1 Issuance
  • 6.2 Presentation
• 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

This attestation addresses the following question:

Where does the responsible economic operator operate his business, and what unique identifiers are associated to a site?

The Site Attestation provides a standardized, verifiable digital representation of a specific physical location (site) operated by an economic operator. It enables structured exchange of site-level data for use in KYS (Know Your Supplier), KYC (Know Your Customer), supply chain mapping, compliance verification, and regulatory audit processes.

A site is defined as an operational business element conducted by a specific economic operator entity at a specific physical location. An economic operator is a role of a European Business Wallet Owner (EBW owner).

The Site Attestation is NOT designed to provide Economic Operator specific data such as NACE code, tax information, nor attestations regarding the operating Economic Operator. These data are provided by EBW owner attestations like EUCC, EBWOID, and others. The site attestation MUST be linked to the economic operator by providing at least one unique identifier associated to the Economic Operator.

Transparency in supply chain requires clarity about location and operation of an economic operator's sites, for example to define incoterms, track products, or calculate CO2eq emissions.

Examples:

• A legal entity delivers goods to 10 other companies and operates from a hired site.
• A legal entity operates in 100 manufacturing sites and has to declare from which site the product is delivered.

The added value for a company to have "site" as an attestation is to automate contracting processes in offering, delivering, creating digital product passports and reporting, customs and other authorities.

Economic Operator attestations (like EUCC, LEI, DUNS legal entity, ...) help to answer KYC/KYS questions like:

• Who signs the contract?
• Who bears liability?
• Corporate hierarchy?

The Site Attestation helps to answer questions like:

• Where does the work get performed?
• Which facility is in scope?
• What operational risk do we have?
• For which establishments do we need which compliance attestations? (e.g., ISO 9000, ...)

Together, they support key KYC/KYS topics:

• Multi-site suppliers
• Site-specific approvals
• Regulatory audits
• Supply-chain mapping

1.1 Document scope and purpose

The Site Attestation provides a standardized, verifiable digital representation of a specific physical location (site) operated by an economic operator. It enables structured exchange of site-level data for use in KYS (Know Your Supplier), KYC (Know Your Customer), supply chain mapping, compliance verification, and regulatory audit processes.

The attributes listed in this attestation are required to automate cross-business processes within supply management.

Design Decisions

This Site Attestation Rulebook is based on:

• European Business Wallet (EBW) framework and vocabulary v0.1 for economic operator identity linkage
• The Organization Ontology for site naming
• Core Location Vocabulary for address and site identifier structures
• CDDL representation types per [RFC 8610] for attribute encoding
• International Code Designator (ICD) 0243 for BPNL/BPNS identifiers as used in Catena-X
• Support for multiple site and economic operator identifier schemes (EUID, LEI, DUNS, EORI, VAT ID, BPNL, GLN, SIREN, BPNS, SIRET)

Note: EUID is only available and mandatory for legal entities within the EU. Legal entities outside the EU, for which the EUCC is not available, can use the DUNS Legal Entity, LEI Legal Entity, or GLN Legal Entity attestation.

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.

Where the attestation is issued as a qualified electronic attestation of attributes, the trust model of chapter 10 applies in its qualified form and the legal category recorded in section 4.1 changes accordingly.

2.3 Traceability

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

3 Attestation attributes

The Site Attestation provides a standardized, verifiable digital representation of a specific physical location (site) operated by an economic operator. It captures the essential attributes required to uniquely identify a site, link it to its operating economic operator, and support cross-business processes within supply chain management and compliance verification.

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 data model for the Site Attestation is structured as follows:

Data Model: [Economic Operator] ---operates--- [Site] [1 - 1 ]

├─ name (string), mandatory
├─ identifier (uuid), mandatory
├─ additional_identifiers - optional 
│   ├─ gln (str) (O)                          // Global Location Number for site 
│   ├─ duns (str) (O)                         // duns number for site 
│   ├─ bpns (str) (O)                         // Business Partner Number Site
│   ├─ siret (str) (O)                        // Système d'Identification du Répertoire des Établissements
├─ address (Address) (M)           
│   ├─ street (tstr) (M)
│   ├─ house_number (tstr) (M)
│   ├─ locality (tstr) (M)
│   ├─ region (tstr) (M)
│   ├─ postal_code (tstr) (M)
│   └─ country (tstr) (M)                       // ISO 3166-1 alpha-2
└─ additional_addresses [0..n]                  //(Array of Address) 
│   ├─ street (tstr) (M)
│   ├─ house_number (tstr) (M)
│   ├─ locality (tstr) (M)
│   ├─ region (tstr) (M)
│   ├─ postal_code (tstr) (M)
│   └─ country (tstr) (M)                       // ISO 3166-1 alpha-2
├── economic_operator (M) 
│   ├─ identifier  (M)                    
│   │   ├─ euid (str) (O)                       // European Unique Identifier
│   │   ├─ lei (str) (O)                        // Legal Entity Identifier per ISO 17442
│   │   ├─ tax (str) (O)                        // National tax or registration number    
│   │   ├─ gln (str) (O)                        // Global Location Number for legal entities, GS1 identifier
│   │   ├─ duns (str) (O)                       // Data Universal Numbering System, Dun & Bradstreet identifier
│   │   ├─ eori (str) (O)                       // Economic Operators Registration and Identification number, EU customs identifier
│   │   ├─ bpnl (str) (O)                       // Business Partner Number Legal entity, Catena-X identifier per ICD 0243
│   │   ├─ siren (str) (O)                      // Système d'Identification du Répertoire des ENtreprises, French company identifier

Note: M - mandatory / O - optional.

Explanation:

• The root object of the attestation is the Site.
• A Site is defined by its mandatory name, a unique identifier (UUID), and its primary address.
• It is optionally possible to add additional_identifiers (like GLN, DUNS, BPNS for the site) and a list of additional_addresses.
• Each Site attestation SHALL contain a mandatory economic_operator object, which links the site to the legal entity that operates it.
• The economic_operator object SHALL contain an identifier object with at least one official identifier of the legal entity (e.g., euid, lei, bpnl).

Attestation Classification:

This attestation type is classified as:

• "EAA" when self-issued by the economic operator operating the site.

Top-Level Data Identifiers:

3.2 Mandatory attributes

Site Attributes

Nested Mandatory Attributes

Applies to both site_main_address and entries within site_additional_addresses:

3.3 Optional attributes

Economic Operator Identifier Optional Attributes At least one of the following sub-fields SHALL be provided within the economic_operator.identifier object.

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 Economic Operator Identifier Type Codes

The economic_operator.identifier object SHOULD use one or more of the following standardized identifier types as keys:

4.4.2 Site Identifier Type Codes

The additional_identifiers object SHOULD use one or more of the following standardized site-level identifier types as keys:

4.5 Integrity rules

• The root Site object SHALL be present.
• name, identifier, address, and economic_operator SHALL be present and non-empty.
• The identifier for the site SHALL be a valid UUID.
• The economic_operator.identifier object SHALL contain at least one valid, non-empty identifier sub-field.
• All Address objects SHALL contain non-empty street, house_number, locality, postal_code, and country.

5 Formats

5.1 SD-JWT VC-based encoding

The Site Attestation uses the SD-JWT VC format to allow for selective disclosure.

Verifiable Credential Type (vct): eu.we-build:site: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/site/2026",
    "status_list_index": 789,
    "status_purpose": "revocation"
  }
}

5.1.3 Example Payload

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

{
  "vct": "eu.we-build:site:1",
  "iss": "did:example:robert-bosch-gmbh",
  "iat": 1746000000,
  "exp": 1777536000,
  "attestation_legal_category": "EAA",
  "name": "Bosch Karlsruhe Manufacturing Site",
  "identifier": "urn:uuid:550e8400-e29b-41d4-a716-446655440000",
  "additional_identifiers": {
    "bpns": "BPNS0000000001XY",
    "gln": "4012345000016"
  },
  "address": {
    "street": "Auf der Breit",
    "house_number": "4",
    "locality": "Karlsruhe",
    "region": "Baden-Württemberg",
    "postal_code": "76227",
    "country": "DE"
  },
  "additional_addresses": [
    {
      "street": "Robert-Bosch-Strasse",
      "house_number": "2",
      "locality": "Karlsruhe",
      "region": "Baden-Württemberg",
      "postal_code": "76131",
      "country": "DE"
    }
  ],
  "economic_operator": {
    "identifier": {
      "euid": "DE.HRB.12345",
      "bpnl": "BPNL00000003CML1"
    }
  },
  "status": {
    "type": "status-list",
    "status_list_credential": "https://issuer.example.com/status/site/2026",
    "status_list_index": 789,
    "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/site-attestation-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

@TODO, To be discussed: which stakeholders will support this format and which use cases require it.

6 Protocols

6.1 Issuance

This attestation is issued using OpenID for Verifiable Credential Issuance [OpenID4VCI], as profiled by [HAIP].

6.2 Presentation

This attestation is presented using OpenID for Verifiable Presentations [OpenID4VP]. Only remote presentation is in scope, consistent with chapter 5, which records the mdoc encoding as out of scope.

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.

For QEAA (Qualified Issuance):

• The issuer-either a Qualified Trust Service Provider (QTSP) or another authorized competent body-must issue and verify the attestation exclusively on the basis of authoritative sources, such as official company register data or audited financial statements.
• The issuer is also responsible for maintaining a high level of assurance throughout the attestation's validity period by continuously monitoring the underlying information. If any change affecting the accuracy or validity of the attested data is detected, the issuer must promptly revoke the attestation.

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.

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.

Revocation Triggers & Business Rules

• QEAA Trigger (Automatic): The QTSP/competent body must actively monitor official company register data and audited financial statements. Any detected discrepancy or change in the company registry must automatically trigger revocation of the QEAA.
• 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 Relying Party obligations of 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 not in scope, consistent with chapter 5, which records the mdoc encoding as out of scope.

9.3 Transactional data

This Rulebook defines no transactional data.

10 Trust Framework

The trust anchor is obtained as described in the branch below that corresponds to the legal category under which the attestation was issued.

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

Qualified Electronic Attestations of Attributes (QEAAs)

For QEAAs, trust is established through the X.509 Public Key Infrastructure (PKI) and the applicable Trust List of Licensees (TLOL). The issuer's certificate chain, including the intermediate certificate contained in the QEAA header, SHALL be validated up to a trusted root certificate. This validation SHALL be performed using the applicable TLOL, taking into account the trust list state applicable at the time of issuance.

Successful certificate chain validation establishes that:

• the issuer's certificate was recognized within the applicable trust framework;
• the issuer's identity has been validated by the supervisory authority during inclusion in the TLOL; and
• the issuer satisfies the trust requirements applicable to QEAAs.

In addition, the Relying Party MAY apply further authorization checks based on its internal policies, such as maintaining a whitelist of accepted QEAA providers.

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