In authentication, which entity is responsible for verifying the claimed identity?

• A. The Verifier
• B. The Prover
• C. The Client
• D. The Sender

Answer: (A)

Verifying a claimed identity is about checking the evidence that someone presents to prove who they are. The entity that does this check is the verifier. It receives the credentials or challenge responses from the prover and decides whether they match the trusted data stored or known by the system. The prover is the one who presents the evidence of identity—such as a password, a certificate, or a signed token. The client is simply the party initiating the interaction and isn’t necessarily the one validating credentials. The sender isn’t a standard role in authentication.

For example, when you log in to a service, the service acts as the verifier: it hashes the password you provide and compares it to the stored hash, and if they match, your identity is verified and access is granted.