How the Online Certificate Status Protocol and OCSP Stapling work & more - Sectigo Team, Security Boulevard

The Online Certificate Status Protocol (OCSP) allows clients (e.g., web browsers) to verify the validity of digital certificates in real time. Certificate Revocations Lists (CRLs), are lists of digital certificates that have been revoked by the issuing Certificate Authority (CA) before their scheduled expiration date, can also be used to check untrustworthy or revoked certificates. However, due to CRLs being updated at intervals and providing stale information and also OCSP responses being smaller than CRL files and suitable for devices with limited memory they are often preferred. Let’s look at how OCSP works, its pros and cons, the potential privacy concerns OCSP stapling helps solve, and how OCSP differs from certificate revocation lists (CRLs).

https://securityboulevard.com/2024/01/how-the-online-certificate-status-protocol-and-ocsp-stapling-work-more/