Selective disclosure

Selective disclosure lets an EUDI Wallet user share only needed attributes, like proving age without revealing a birth date, per GDPR data minimisation.

Selective disclosure means a wallet user shares only the attributes a relying party actually needs - proving "over 18" without revealing the birth date (provided the issuer included an attribute such as age_over_18), or "registered pharmacist" without the registration number. It is the privacy cornerstone of the EUDI Wallet and a direct application of GDPR data minimisation. Regulation (EU) 2024/1183, which amends the eIDAS Regulation, requires wallets to support selective disclosure of attributes.

Technically it is built into the credential formats: SD-JWT hashes each attribute separately so the holder can reveal a subset, and mdoc supports per-element disclosure. The attestation is issued once; what gets shown is decided per presentation. Selective disclosure limits what is shown but does not by itself guarantee unlinkability: if a relying party recognises the same issuer signature or attestation across multiple presentations, it may still be able to correlate them.