What is typically included in the confirmed list of revoked certificates provided by the CRL?

• A. Active public keys
• B. Expired certificates
• C. Invalidated certificates
• D. All digital signatures

Answer: (C)

The confirmed list of revoked certificates provided by a Certificate Revocation List (CRL) typically includes invalidated certificates. When a certificate is revoked, it means that it is no longer trusted. This could happen for various reasons, such as if the private key has been compromised, if the certificate was issued to someone who is no longer authorized, or if the information in the certificate is no longer valid.

A CRL is an essential component of Public Key Infrastructure (PKI) and helps in maintaining the integrity and security of communications by ensuring that only valid certificates are used for encryption and authentication. By including only invalidated certificates, the CRL allows users and systems to check the status of certificates in real-time, ensuring that any security risks associated with revoked certificates can be mitigated.

While active public keys and expired certificates may be related to certificate management, they are not part of the CRL. Active public keys represent currently valid certificates, and expired certificates may still be in circulation but do not imply revocation. Similarly, digital signatures represent verified transactions or communications but are not included in a CRL. Therefore, it is the invalidated certificates that form the core content of a CRL.