Privacy by Design
privacyFull Name: Privacy by Design and Default
Definition
Privacy by Design is a framework that requires privacy considerations to be embedded into the design, operation, and management of information technologies and systems throughout their entire lifecycle. Originally developed by Dr. Ann Cavoukian, former Information and Privacy Commissioner of Ontario, Canada, the concept became a legally binding requirement in the European Union through GDPR Article 25. For the EUDI Wallet, Privacy by Design is not merely a best practice but a fundamental architectural principle that shapes every aspect of how the wallet stores, processes, and shares personal identity data across the European digital identity ecosystem.
Privacy by Design in the EUDI Wallet Architecture
The EUDI Wallet architecture embodies Privacy by Design through its decentralized, user-centric model. Unlike centralized identity systems where a single authority stores and manages all user data, the EUDI Wallet stores credentials locally on the user's device. This means there is no central database of citizen identity information that could be breached, leaked, or surveilled. The user maintains direct control over their personal data at all times.
Selective disclosure is one of the most powerful Privacy by Design features of the EUDI Wallet. When a verifier requests information, users can choose to share only the specific attributes needed. For example, when proving eligibility to purchase age-restricted products, the wallet can confirm that the user is over 18 without revealing their exact birthdate, name, or address. This data minimization approach ensures that verifiers never receive more personal information than strictly necessary.
The wallet architecture also implements unlinkability, ensuring that different verifiers cannot correlate a user's transactions to build a complete profile. Each credential presentation uses unique session identifiers, preventing a scenario where a bar, a bank, and a government office could combine their records to track an individual's movements and activities.
The Seven Foundational Principles
The EUDI Wallet addresses all seven foundational principles of Privacy by Design. Proactive prevention means that privacy risks are identified and mitigated during the design phase through threat modeling and privacy impact assessments. Privacy as the default setting ensures that the wallet shares no data without explicit user consent and that the minimum necessary data is included in each presentation.
Privacy embedded into design is reflected in the architecture itself, with local data storage, end-to-end encryption, and secure enclave key management built into the core specification. Full functionality ensures that privacy does not come at the cost of usability; the wallet must be as convenient as showing a physical ID card while providing far superior privacy protections. End-to-end security covers the entire credential lifecycle from issuance through storage, presentation, and eventual deletion.
Visibility and transparency require that the wallet clearly communicates what data is being requested, by whom, and for what purpose before each transaction. Users must be able to review their transaction history and understand what information has been shared. Respect for user privacy places the individual at the center of the system, with the wallet acting as their agent rather than as a tool of the government or private sector.
Legal Requirements and Compliance
GDPR Article 25 requires data controllers to implement appropriate technical and organizational measures both at the time of determining the means for processing and at the time of the processing itself. For EUDI Wallet providers, this means conducting Data Protection Impact Assessments (DPIAs) before deployment, implementing privacy-enhancing technologies like zero-knowledge proofs where feasible, and ensuring that the default configuration of the wallet maximizes privacy protection.
The eIDAS 2.0 regulation reinforces these requirements by explicitly mandating that the EUDI Wallet must not allow wallet providers to collect information about user transactions, must support selective disclosure, and must enable pseudonymous authentication where full identification is not required. These regulatory requirements transform Privacy by Design from an abstract principle into concrete, enforceable technical specifications.
Member states implementing the EUDI Wallet must demonstrate compliance with both GDPR and eIDAS 2.0 privacy requirements through independent audits and certifications. The European Data Protection Board (EDPB) provides guidance on how these requirements should be interpreted and implemented in the context of digital identity wallets, ensuring consistent privacy protections across all 27 member states.