In PKI, which component serves as the database of active digital certificates for a CA?

• A. Certificate Authority
• B. Registration Authority
• C. Repository
• D. Archive

Answer: (C)

In PKI, the database that stores the certificates currently in use is the certificate repository. This repository publishes issued certificates so relying parties can retrieve a subject’s public key, verify the certificate’s validity period, confirm the issuer, and build the trust path to verify signatures. It acts as the directory of active certificates that clients query when they need to encrypt data for someone or verify a digital signature.

The Archive serves a different purpose: it keeps older certificates, including those that have expired or been revoked, for audit and recovery purposes. The Certificate Authority is the entity that issues and signs certificates, while the Registration Authority handles identity verification on behalf of the CA.