The EUDI Wallet Architecture & Reference Framework in Plain English

May 18th, 2022

In June 2021, the European Commission took a giant step toward making a citizen’s day-to-day life a piece of cake: announcing a new EU Digital Identity with a digital ID Wallet as a key component. The ID Wallet has been an essential piece of the SSI architecture since day 1, and we’re excited to see it being prioritized at a regional level for all public and private digital identity processes.

About 2 months ago the EU published a EUDI Architecture and Reference Framework - the first public documentation since June 2021. It serves as a guide to explain the general objective of the EUDI Wallet, ecosystem actors and roles, functional/non-functional requirements, and potential building blocks. While the document does not explicitly refer to the concept of Self-Sovereign Identity (SSI), its underlying concepts and overall goal coincide with the SSI vision and mission as it emphasizes privacy, user-control, and user-friendliness. In its own words:

“The primary objective of the proposed European Digital Identity Wallet is to promote trusted digital identities for all Europeans allowing users to be in control of their own online interactions and presence.”

General points:

  • This reference framework includes many actors and roles which had not been originally recognized by the SSI ecosystem or had been referenced as functional components rather than roles.
  • As expected, there is a strong focus on user control, user privacy, and selective disclosure
  • The Wallet will be mandatory for Member states to provide but will be optional for citizens to adopt

eIDAS 2.0 Toolbox & Status

eidas2 0timeline

With the expected launch date of the EUDI Wallet being Q1 2024, the eIDAS 2.0 toolbox and regulation are being worked on by the eIDAS expert group comprised of representatives from the 27 member states; the process is being organized in 4 sub-working groups, each concerned with a separate feature or functionality of the toolbox.

At the same time, the European Commission is incentivizing Member States to start adopting the new regulation by means of a €37M grant to support the implementation of 4 large-scale pilots. Worth highlighting Digital Credentials for Europe (DC4EU), a 22-member consortium that will present two use cases in addition to the onboarding of a base identity: Educational credentials & professional qualifications and Social Security.

eIDAS 2.0 Roles adapted to the SSI ecosystem

So far, the EU has defined 14 basic roles and actors for the EUDI ecosystem and the majority can be re-categorized into SSI stakeholder categories: Issuer, Holder, and Verifier.

For those that fall under the Issuer umbrella, the eIDAS toolbox distinguishes 3 different roles relative to the type of data they issue: personal data, official & non-official attributes. Additionally, it has emphasized other types of providers, which SSI has not yet identified as roles or entities themselves, but rather as sources of information (or registries): Schema Catalogue Provider, Authentic Source provider, and Providers of Registries of Trusted Sources.

Interestingly, eIDAS extends the definition of the Provider of registries of trusted sources to also include trusted lists of verifiers and wallet providers, information that is not included in typical SSI implementation.

There have also been new roles/actors added that had been uncontemplated by the SSI ecosystem: Conformity Assessment Bodies (CAB) and Supervisory Bodies, which certify and supervise EUDI Wallet, qualified and non-qualified trust service providers respectively. For your reference and easier understanding, we have arranged and adapted the eIDAS roles into an SSI stakeholder map for a clearer visualization of information and relationship flow - see below.

eidas2 0roles

A look into the functional requirements

In this next section, we’ll dive into the most important functional requirements established by the eIDAS Toolbox, and aim to explain them in simpler, casual English.

For more complicated section titles, we included an alternative, simpler title which catches the gist of the original titles' intention.

Section 4.1: Store person identification data, qualified electronic attestation of attributes, and electronic attestation of attributes

Plain English section summary:

Storing personal data in the Wallet

  • Wallets have to be able to store and manage personal data on their smartphone (locally) or remotely (in-cloud).
  • As in SSI, users have to be able to receive their Verifiable Credentials, store them in their Wallet, and share these credentials without having to ask the issuer.

Section 4.2: Request and obtain person identification data, qualified electronic attestation of attributes and electronic attestation of attributes

Plain English section summary:

Requesting and obtaining personal data in the Wallet

  • Wallet must allow organizations to request and obtain user personal data during onboarding/authentication. For example Bank asks user for a National ID verifiable credential in the “create your bank account process”.
  • Users should be able to request personal data credentials from issuers. Users should also be able to delete data from their wallets.

Section 4.3: Cryptographic functions

Plain English section summary:

Access and management of cryptographic functions

  • This section mainly emphasizes the correct use of cryptographic functions (keys, computation, environments). The Wallet should be able to create, store, use and delete cryptographic material (ie. keys).
  • Users should have secure access to cryptographic functions (ie. cryptographic keys) wherever they are hosted.

Section 4.4: Mutual authentication

Plain English section summary:

Entities, users, and wallets authenticating each other

  • EUDI Wallet must be able to recognize and identify organizations it is interacting with, and vice versa. For example, when logging into a student portal, Alice’s wallet must be able to recognize the student portal, and the student portal must be able to recognize Alice’s Wallet and that it is certified.
  • These actions should be possible both online and offline.
  • There must be a standard specified as EU level interoperability is required.

Section 4.5: Selection, combination and sharing of person identification data, qualified electronic attestation of attributes and electronic attestation of attributes

Plain English section summary:

Selecting, combining, and sharing personal data

  • Users should be able to use their EUDI Wallet as a method of authentication (prove their identity). This digital form of proving who they are will have legal validity.
  • The Wallet should follow standard presentation interfaces to communicate and share the user’s data in an effort to make it interoperable at European level.
  • The Wallet Provider cannot see/store any user information unless it is absolutely necessary for it to continue providing the service.
  • The Wallet is required to have the possibility of sharing information through selective disclosure mechanisms. This enables users to shares bits of their identity without revealing all of their attributes. For example, to prove her age at a liquor store, thanks to selective disclosure, Alice would only share her full name and birthdate information. The rest would be hidden from the liquor store.
  • In an offline (in-person) scenario, if a user shares their attributes which are not directly linked to their EUDI Wallet (for example the Covid Health Certificate), they may have to support it with additional documentation.
  • In an online scenario, when proving their identity through the sharing of personal data via their Wallet, users must be able to prove they control or have access to the cryptographic keys linked to the information being shared. “My keys, my Wallet, my info”

Section 4.6: User interface for user awareness and authorization mechanism

Plain English section summary:

Maximizing user experience and transparency

  • This section is all about the user-friendliness of the the EUDI Wallet
  • User should be able to clearly know/see:

    • Who they’re interacting with (issuers, verifiers, wallets, registries etc)
    • The reason third parties request particular information
    • Their data protection rights
    • Which data is mandatory in order to be authenticated and which is optional
    • The history or log of events of the wallet’s use (for ex. when they’ve shared a credential, been issued a credential, linked to a service)
  • The Wallet should follow privacy and security-by-design principles, which includes specifically requesting users to clearly express their consent to sharing information.
  • The Wallet has to allow two-factor authentication

Section 4.7: Sign by means of qualified electronic signature or seal

Plain English section summary:

Being able to sign and seal digitally

  • The Wallet must allow its user to digitally sign documents and data


The first outline for the European Digital Identity Architecture and Reference Framework has provided a solid foundation for the main requirements and objectives of the EUDI Wallet. SSI providers were especially keen to review this document given many have production-ready Wallets that need to be adapted to include all the requirements laid out by the future toolbox. It was a great start to see what types of requirements, both functional and non/functional, we will need to keep in mind and prepare to adapt. We’re looking forward to the evolution of this framework in order to see which specific mechanisms and methodologies will appropriately gear and guide Wallet providers for accurate implementation.

The reference framework currently emphasizes data privacy, highlighting selective disclosure protocols, and interoperability, requiring it at a European level at minimum - two essential characteristics for the usability and security of the EUDI Wallet. We will have to wait for further details on how exactly European interoperability will be guaranteed, which is a long-time goal SSI enthusiasts have been working on. Other key points we're hoping the updated document expands on are high Level of Assurance (LOA), two factor authentication (2FA), and security requirements. We were able to catch a glimpse of these, however little was mentioned when it came to their development and implementation.

As for governance, we’re especially curious to see how the potential complexity of the EUDI Wallet certification process driven by these factors, along with the selectivity from Member States, can threaten the competitiveness of the Wallet provider market.

We’re looking forward to seeing eIDAS 2.0 Toolbox progress as well as adapting the GATACA Wallet to its specifications.

Photo by Waldemar Brandt on Unsplash

Chat with us - We’d love to chat with you. Let us know your perspective and comments on this topic or anything Digital Identity-related. Join our Telegram group.

Stay in the loop - Keep yourself updated on GATACA developments and how digital identities will transform our digital lives here.

Have a specific topic you’d like us to cover? Email us at - we’ll break it down for you in our upcoming blog articles.