certifikatrevocation

Certificate revocation is the process of invalidating a digital certificate before its scheduled expiration date. Digital certificates, often used in Public Key Infrastructure (PKI) to authenticate identities online, can become untrusted for various reasons. These reasons include the compromise of the private key associated with the certificate, a change in the information stated in the certificate (such as the subject's name or organization), or the issuing Certificate Authority (CA) ceasing operations.

When a certificate is revoked, it means that relying parties, such as web browsers or other software applications, should no longer trust it. This prevents malicious actors from impersonating legitimate entities or using compromised certificates for fraudulent purposes.

There are several mechanisms for checking if a certificate has been revoked. The most common are Certificate Revocation Lists (CRLs) and Online Certificate Status Protocol (OCSP). CRLs are lists published by CAs that contain the serial numbers of all revoked certificates. OCSP provides a real-time query mechanism, allowing a client to directly ask a CA's OCSP responder about the status of a specific certificate. Both methods are crucial for maintaining the security and trustworthiness of digital communications.