1. Online Certificate Status Protocol ‘OCSP’ Dave Hirose July 15 2004 Outline: What is OCSP? Digital Signatures Certificate Revocation List Technical aspects of OCSP Types of OCSP Conclusions

2. OCSP & Digital Signatures OCSP is a protocol used to verify the status of digital signatures Digital Signatures

3. Certificate Status Certificate Revocation Lists & OCSP

4. Technical details of OCSP Request Protocol version Service request Target certificate identifier Optional extensions which may be processed by the OCSP Response Version Responder’s name Responses for each of the certificates in the request Possible Responses: Good Revoked Unknown

5. Types of OCSP Trusted Distributed

6. Conclusion Can be useful in certain situations. Suitable for highly sensitive or high valued information Weigh the risk of not using real time verification against the cost of using and implementing it Should consider checking the CRL directly for revoked certifications. OCSP is not infallible. Since the revocation lists are not locked. If real time verification of certificates is imperative and you have a high volume complicated system, you should consider using a vendor specializing in digital certificate validation

7. Online Certificate Status Protocol Questions?