What does the Certificate Revocation List (CRL) provide?

The Certificate Revocation List (CRL) serves a crucial role in the public key infrastructure (PKI) by providing a list of revoked digital certificates. When a certificate is no longer valid before its scheduled expiration date, it must be revoked to prevent its fraudulent use. The CRL enables users and systems to check the status of certificates to ensure that they have not been revoked and are still trustworthy.

This capability is vital for maintaining the integrity and security of communications, as it helps mitigate risks associated with compromised or misused certificates. A CRL is created and digitally signed by the Certificate Authority (CA) that issued the certificates. Users and systems can download this list periodically to stay informed about the current status of digital certificates.

In contrast, a list of active certificates, all issued certificates, or pending certificate requests does not represent the primary function of the CRL. These alternative lists would typically be managed or accessed differently within the PKI framework and would not serve the critical purpose of indicating revoked certificates that should no longer be trusted.