OCSP (Online Certificate Status Protocol)

The Online Certificate Status Protocol (RFC 6960) lets a client check whether an X.509 certificate has been revoked by querying a responder run by the issuing CA, returning a signed status. OCSP is faster and less bandwidth-intensive than downloading full CRLs but introduces availability and privacy concerns, mitigated by OCSP Stapling (RFC 6066) where the server presents the response.

Categories: Security ControlsProtocols and StandardsRegulation and Compliance

OCSP in context

Security controls span signaling firewalls (SS7/Diameter/GTP screening), transport encryption (IPsec, TLS, PRINS), identity and access on OSS/BSS, and monitoring at both packet and log level. Controls are audited against GSMA FS.11/FS.19/FS.20/FS.36.

Telecom security is written into standards from 3GPP, GSMA, ETSI, IETF and ITU-T. Understanding which body owns which specification, and how they interlock, is essential for both design and audit work.

To place OCSP in the wider telecom-security picture, review 3G, 6G, AES, A5/1, CAMARA Project and Cipher Downgrade Attack — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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