The correct answer is the Certificate Revocation List (CRL). A CRL is a list maintained by a certificate authority (CA) that contains identifiers for all certificates that have been revoked before their scheduled expiration dates. This can occur for various reasons, such as if the private key has been compromised, the owner no longer needs the certificate, or if the organization has been dissolved.
When users or systems need to establish trust in a certificate, they can refer to the CRL to determine if the certificate is still valid or if it has been revoked. The CRL provides a comprehensive and authoritative listing of such certificates, ensuring that parties can make informed decisions regarding trust relationships in secured communications.
While OCSP, another option, is a protocol used for obtaining the revocation status of a specific certificate in real time, it does not provide a comprehensive list of all revoked certificates like a CRL does. PKI refers to the overall framework that manages keys and certificates, but it is not a specific location where you would find a list of revoked certificates. The CA Repository serves as a storage location for issued certificates and CRLs, but it is not the specific listing of revoked certificates itself. Thus, the CRL is the definitive source for finding such information.