Issuer: An entity that issues a credential. Eg: a test management facility like a hospital that issues a patient record like “Covid -ve“. Issuer has the right to revoke a credential
Holder: An entity that has lifecycle control over the issued credentials like sharing, deleting. Eg: A patient that holds a credential issued by an issuer on their wallet (a wallet could be an app that stores users credential data locally or a custodial wallet managed on behalf of a holder)
Verifier: An entity that verifies if the credential shared by a holder is valid (i.e. if the credential comes from a trusted issuer, not revoked by the issuer). Eg: An access management system installed at a facility like airport that allows / denies access based on if the holder is covid -ve/+ve. Verification could be a combination business logic like “is the credential is issued in the last 14 days” and “is it issued by an issuer that is recognized“
Note: One entity can play multiple roles. Eg: A hospital can play the role of a verifier and an issuer
Here are some basic terminologies used in the SSI ecosystem: https://www.w3.org/TR/vc-data-model/#terminology
Last Updated: 10 November 2021