What do the base register and the trust register of the Swiss trust infrastructure store, and what do they never store?
The base register holds the identifiers and public keys of issuers and verifiers and the revocation status of credentials; the trust register confirms who is behind those identifiers. Neither ever stores personal data from individual credentials.
| Register | Purpose | Example question it answers |
|---|---|---|
| Base register | Technical anchors: identifiers (DIDs) and public keys of issuers and verifiers, plus credential status lists for revocation | "Which key belongs to this issuer identifier, and is credential no. 4711 still valid?" |
| Trust register | Trust anchors: confirms the real-world identity behind an identifier and its trust level | "Is this identifier really fedpol, and not someone pretending to be?" |
The split matters. A valid signature only proves that someone with that key signed. The trust register is what tells a verifier that this someone is an authority it should believe.
And the most important line: no personal data of individual credentials goes into either register. That is the SSI property of "no central store of identity data, only confirmations in registers" applied in practice.
Go deeper:
swiyu technical documentation — how issuers and verifiers onboard to the base and trust registers.