Normative Language 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.

Defined Terms

The terms User, Trust Service, Trust Model, Trusted List, Trust Framework, Attribute, Electronic Attestations of Attributes Provider or Trust Service Provider (TSP), Person Identification Data (PID), Revocation List, Qualified Electronic Attestations of Attributes Provider or Qualified Trust Service Provider (QTSP), Electronic Attestation of Attributes (EAA), are defined in the EIDAS-ARF.

Below are the description of acronyms and definitions which are useful for further insights into topics that complement the it-wallet and the interacting components.

Name	Description	Notes
User	A natural or legal person, or a natural person representing another natural person or a legal person, that uses a trust services or electronic identification means provided in accordance with EUDI Wallet Architecture Reference Framework. [ARF v1.4]
User Attribute	A characteristic, quality, right or permission of a natural or legal person or of an object. [ARF v1.4]	Other alternative terms: User Claim
Digital Identity Provider	Entity responsible for identifying citizens for the issuance of a digital identity.
Digital Credential	A signed set of Attributes encapsulated in a specific data format, such as mdoc format specified in [ISO 18013-5] or the SD-JWT VC format specified in [SD-JWT-VC]. This may be a Personal Identification Data (PID), (Qualified) Electronic Attestation of Attribute ((Q)EAA). [Revised from ARF v1.4]	Differences with ARF: The definition from ARF restricts the data format to mdoc and SD-JWT VC. For the scope of the Trust Model, a Digital Credential definition should be neutral on the format. ARF alternative terms: Electronic Attestation, Attestation. Other alternative terms: Verifiable Credential, Digital Attestation.
Organizational Entity	A legal person (only considering organizations and public entities, not natural/physical persons) recognized by the Member State through a unique identifier to operate a certain role within the EUDI Wallet ecosystem.	In this category the following entity roles are included: Wallet Provider, Credential Issuer, Relying Party, QTSP In general, any kind of Entity that must be registered through a national or European registration mechanism. ARF alternative terms: legal person (only considering organizations and public entities, not natural/physical persons)
Wallet Solution	A Wallet Solution is the entire eIDAS-compliant product and service provided by a Wallet Provider to all Users and certified as EUDI-compliant by a Conformity Assessment Body (CAB). [Revised from ARF v1.4]	Differences with ARF: editorial ARF alternative terms: EUDI Wallet Solution
Wallet Provider	An Organizational Entity, responsible for the management and release operation of a Wallet Solution. The Wallet Provider issues the Wallet Attestations to its Wallet Instances through an Attestation Service. The Wallet Attestation certifies the genuinity and authenticity of the Wallet Instance and its compliance with the security and privacy requirements. [Revised from ARF v1.4]	Differences with ARF: editorial ARF alternative terms: EUDI Wallet Provider
Wallet Instance	Instance of a Wallet Solution installed on a User’s device belonging to and which is controlled by a User. It enables the storage and management of Digital Credentials.The Wallet Instance provides graphical interfaces for User interaction with Relying Parties, PID, (Q)EAA Providers and the Wallet Provider. [Revised from ARF v1.4]	Differences with ARF: editorial ARF alternative terms: EUDI Wallet Instance
Wallet Provider Backend	Is the technical infrastructure and server-side components, including a set of endpoints, managed by a Wallet Provider.
Credential Issuer	An Organizational Entity providing Digital Credentials to Users. It may be PID Provider or (Q)EAA Providers. [Revised from ARF v1.4]	Differences with ARF: (i) merged the PID Providers and (Q)EEA Providers definitions using the general term Digital Credential, (ii) renamed “Member Stare or other legal entity” in “Organizational Entity” ARF alternative terms: PID Providers,(Q)EEA Providers, Attestation Provider Other alternative terms: Verifiable Credential Issuer
Relying Party	An Organizational Entity that relies upon an electronic identification or a Trust Service originating from a Wallet Instance. [Revised from ARF v1.4]	Differences with ARF: renamed “natural or legal person” in “Organizational Entity”.
Relying Party Instance	A Relying Party Instance in the context of a mobile application or a standalone embedded device refers to a specific deployment of the application or device. These instances depend on an User Authentication through a Wallet Instance to confirm User identities before granting access to their functionalities. Each version or environment where the application or device is running, be it a particular release of a mobile app installed on a User's smartphone or a specific embedded device in use, constitutes a separate instance. In case of proximity supervised scenarios, it belongs to and is controlled by a Verifier. [Revised from ARF v1.4]	Differences with ARF: added a sentence on proximity supervised scenarios. Other alternative terms: Verifier App
Verifier	Also known as Credential Verifier. It is a natural person or a legal person using an Relying Party Instance. [New]
Trust	Trust, within the technical field, is the confidence in the security, reliability, and integrity of entities (such as systems, organizations, or individuals) and their actions, ensuring that they will operate as expected in a secure and predictable manner. It is often established through empirical proof, such as past performance, security certifications, or transparent operational practices, which demonstrate a track record of adherence to security standards and ethical conduct. [Revised from ARF v1.4]
Trust Framework	A legally enforceable set of operational and technical rules and agreements that govern a multi-party system designed for conducting specific types of transactions among a community of participants and bound by a common set of requirements. [ARF v1.4]
Trust Model	Collection of rules that ensure the legitimacy of the components and the entities involved in the EUDI Wallet ecosystem. [ARF v1.4]
Trusted List	Repository of information about authoritative entities in a particular legal or contractual context which provides information about their current and historical status. It serves as the bedrock of trust, acting as federative sources that publish the crucial information about root entities within the ecosystem. [Revised from ARF v1.4]	Differences with ARF: added the last sentence
Registration Authority	A party responsible for registering all the Organizational Entities by issuing a Trust Assertion.	ARF: Registrar
Conformity Assessment Body (CAB)	A conformity assessment body as defined in Article 2, point 13, of Regulation (EC) No 765/2008, which is accredited in accordance with that Regulation as competent to carry out conformity assessment of a qualified trust service provider and the qualified trust services it provides, or as competent to carry out certification of European Digital Identity Wallets or electronic identification means. [ARF v1.4]
National Accreditation Bodies (NAB)	A body that performs accreditation with authority derived from a Member State under Regulation (EC) No 765/2008. [ARF v1.4]	Other alternative terms: Accreditation Authority
Trust Evaluation	The process of verifying the trustworthiness of registered Organizational Entities, in accordance with pre-established rules. For example, involving the retrieval and validation of entity configurations and trust chains.	Other alternative terms: Trust Discovery, Trust Establishment
Trust Assertion	Cryptographically verifiable artifact that proves the compliance of an Organizational Entity with known rules and requirements defined within the Trust Model.	Other alternative terms: Verifiable Attestation, Access Certificate
Trust Relationship	Positive outcome of Trust Evaluation, which produces a reliable relationship between Organizational Entities, where one Organizational Entity trusts the other to securely handle data, execute transactions, or perform actions on its behalf.
Metadata	Digital artifact that contains all the required information about an Organizational Entity, e.g., protocol related endpoints and the Organizational Entity’s cryptographic public keys (for the complete list check requirement “Metadata Content”).
Policy Language	A formal language used to define security, privacy, and identity management policies that govern interactions and transactions within a Trust Framework. This language allows for the clear and unambiguous expression of rules and conditions, facilitating the automation of processes and interoperability among different systems and organizations.
Registration Process	Process performed by a Registration Authority verifying necessary information to ensure Organizational Entity eligibility and compliance with the relevant rules and standards. The main goal of the Registration Process is for the Organizational Entity to receive one or more Trust Assertions to be used for the Trust Evaluation processes.
Accreditation Process	Process performed by the National Accreditation Body to accreditate CABs. As a result of the Accreditation Process, a NAB issues an accreditation certificate to a CAB.	Currently, out of scope of the Trust Model requirements
Certification Process	Process performed by Conformity Assessment Bodies to certify the Wallet Solution. The Certification Process aims to periodically assess technical Wallet Solutions (e.g. performing vulnerability assessment and risk analysis). As a result of the Certification Process a certification is provided to the Wallet Solution. [New]	Currently, out of scope of the Trust Model requirements
Notification Process	Process defining how information is transferred to the European Commission and the inclusion of an entity in the Trusted List.
Supervision Process	Process performed by a Supervisory Body to review and ensure proper functioning of the Wallet Provider and other relevant actors.	Currently, out of scope of the Trust Model requirements
Federation Authority	A public governance entity that issues guidelines and technical rules, and administers - directly or through its intermediary - Trusted Lists, services, and accreditation processes, the status of participants, and their eligibility evaluation. It also performs oversight functions.
Wallet Secure Cryptographic Application	An application that manages critical assets utilizing the cryptographic functions provided by the Wallet Secure Cryptographic Device.
Wallet Instance	The application installed and configured on a Wallet User’s device or environment, which is part of a Wallet Unit, and that the Wallet User uses to interact with the Wallet Unit.
Wallet Unit	Unique configuration of a Wallet Solution that includes Wallet instances, Wallet Secure Cryptographic Applications, and Wallet Secure Cryptographic Devices provided by a Wallet Provider to an individual Wallet User.
Wallet Unit Attestation	Also known as Wallet Attestation or Wallet Instance Attestation, it is a data object issued by a Wallet Provider that describes the components of the Wallet Unit. It allows authentication and validation of those components, and is cryptographically bound to Wallet Secure Cryptographic Devices.
Wallet Secure Cryptographic Device (WSCD)	Hardware-backed secure environment for creating, storing, and/or managing cryptographic keys and data. A WSCD MAY implement an association proof in different ways. This largely depends on the implementation of the WSCD for example: remote HSM, external smart card, internal UICC, internal native cryptographic hardware, such as the iOS Secure Enclave or the Android Hardware Backed Keystore or StrongBox
Credential Status Attestation	Verifiable Attestation proving that a related Digital Credential is not revoked.
Device Integrity Service	A service provided by device manufacturers that verifies the integrity and authenticity of the app instance (Wallet Instance), as well as certifying the secure storage of private keys generated by the device within its dedicated hardware. It's important to note that the terminology used to describe this service varies among manufacturers.
Cryptographic Hardware Keys	During the app initialization, the Wallet Instance generates a pair of keys, one public and one private, which remain valid for the entire duration of the Wallet Instance's life. Functioning as a Master Key for the personal device, these Cryptographic Hardware Keys are confined to the OS domain and are not designed for signing arbitrary payloads. Their primary role is to provide a unique identification for each Wallet Instance.
Cryptographic Hardware Key Tag	A unique identifier created by the operating system for the Cryptographic Hardware Keys, utilized to gain access to the private key stored in the hardware.
Key Attestation	An attestation from the device's OEM that enhances your confidence in the keys used in your Wallet Instance being securely stored within the device's hardware-backed keystore. Its content is therefore defined by the operating system manufacturer. For Google Android, the term Key Attestation refers to the Strongbox Key Attestation feature. For Apple iOS, the reference is to the Device Check service, specifically the attestKey feature.
Qualified Electronic Attestation of Attributes (QEAA)	A digitally verifiable attestation in electronic form, issued by a QTSP, that substantiates a person's possession of attributes.
Qualified Electronic Signature Provider	The Electronic Trust Service Provider responsible for the issuing of Qualified Electronic Signature certificates to the User.
Qualified Electronic Attestation of Attributes Provider	Organizational Entity which serves as Credential issuer providing Qualified Electronic Attestations of Attributes (QEAAs).
PID Provider	Organizational Entity which serves as Credential issuer providing Person Identification Data to Users.	Differences with ARF: renamed “Member Stare or other legal entity” in “Organizational Entity”
National Identity Provider	It represents preexisting identity systems based on SAML2 or OpenID Connect Core 1.0, already in production in each Member State (eg: the Italian SPID and CIE id schemes notified eIDAS with LoA High, see SPID/CIE-OpenID-Connect-Specifications).
Relying Party	A natural or legal person that implements an authentication system requiring electronic attribute attestation submissions as an authentication mechanism.
Verifier	See Relying Party
Trust Attestation	Electronic attestation of an entity's compliance with the national regulatory framework, which is cryptographically verifiable and cannot be repudiated over time by the entity that issued it. A Trust Attestation is always related to a particular Trust Framework.
Trust Layer	Architectural component that enables IT-Wallet system participants to establish trust, in terms of reliability and compliance of all participants with the regulatory framework governing the digital identity system.
Trust Model	System defining how the participants of the ecosystem establish and maintain trust in their interactions. The Trust Model outlines the rules and the procedures for the entities (like users, systems, or applications) should validate each other's identities, authenticate, and establish the level of trust before exchanging information.
Level of Assurance	The degree of confidence in the vetting process used to establish the identity of the User and the degree of confidence that the User who presents the credential is the same User to whom the Digital Credential was issued.
Holder Key Binding	Ability of the Holder to prove legitimate possession of the private part, related to the public part attested by a Trusted Third Party.
Holder	Natural or Legal person that receives Verifiable Credentials from the Credential Issuers, manages the Verifiable Credentials within the Wallet, and presents them to Verifiers. The Holder is the User in control of the Wallet.
Pseudonym	Pseudonyms are alternative identifier used to represent an entity (such as a person or organization) without revealing their true identity. It provides a layer of privacy and anonymity while still allowing for consistent authentication and authorization within a system.

Acronyms

Acronym	Description
OID4VP	OpenID for Verifiable Presentation
PID	Person Identification Data
VC	Verifiable Credential
VP	Verifiable Presentation
API	Application Programming Interface
LoA	Level of Assurance
AAL	Authenticator Assurance Level as defined in https://csrc.nist.gov/glossary/term/authenticator_assurance_level
PII	Personally Identifiable Information
WSCD	Wallet Secure Cryptographic Device