What happens to a digital certificate once it is added to a CRL?

Once a digital certificate is added to a Certificate Revocation List (CRL), it is considered revoked and is no longer valid for use in secure transactions. The CRL is a crucial component of Public Key Infrastructure (PKI) and is used to maintain a list of certificates that have been invalidated before their scheduled expiration date. When a certificate appears on this list, it indicates that it should not be trusted for authentication or encryption purposes.

Revocation can occur for various reasons, such as a compromised private key or a change in the status of the entity that holds the certificate. Upon being listed on the CRL, any parties that rely on this certificate are informed that it should be disregarded, ensuring that security is upheld across systems relying on trusted certificate validation. Therefore, once a certificate is included in the CRL, it is effectively untrustworthy, and any further use for authentication or encryption is prohibited.