Certificates

if the website certificate is in CRL that website certificate is outdated

The Online Certificate Status Protocol (OCSP) is used to check the revocation status of a digital certificate in real-time. It does not have anything to do with hiding information. Hiding information within other data is a characteristic of steganography.

• Online Certificate Status Protocol (OCSP): OCSP is a protocol used to check the revocation status of a digital certificate in real-time. It does not maintain a list of all revoked certificates. Instead, when a client (such as a web browser) needs to verify the status of a certificate, it sends a query to an OCSP responder maintained by the Certificate Authority (CA). The OCSP responder then checks its database and responds with the current status of the certificate (e.g., valid, revoked, unknown).

• Certificate Revocation Lists (CRLs): Certificate Authorities do maintain lists of revoked certificates, known as Certificate Revocation Lists (CRLs). CRLs are periodically updated and distributed by CAs. They contain information about certificates that have been revoked before their expiration date.