Quiz Entry - updated: 2026.10.22
What is the difference between a subject, a claimant, a subscriber, a verifier and a relying party?
The subject is the entity being authenticated; it is a claimant while its claimed identity is being checked and a subscriber once it holds an account with bound authenticators. The verifier checks the authenticator output, and the relying party is the service that relies on the result.
| Role | Who it is | In one line |
|---|---|---|
| Subject | The person, device or service behind the request | The "who" of authentication |
| Claimant | The subject during authentication | "I claim to be account X, here is my proof" |
| Subscriber | A subject with an account at a credential service provider and at least one bound authenticator | The legitimate owner of the account |
| Verifier | The component that checks the authenticator output against the credential | Decides "valid or not" |
| Relying party (RP) | The service the subject wants to use | Trusts the verifier's result and opens a session |
The claimant / subscriber distinction captures the point of the whole process: anyone can claim an account, and authentication is what decides whether this claimant really is the subscriber. In the NIST picture, the claimant box turns into the subscriber box once the session is open.
Go deeper:
NIST SP 800-63-4: Digital Identity Model — all the roles, from applicant to subscriber, verifier, CSP and RP.