What is CN OCSP and What Is It Used For?
What is OCSP?
OCSP (Online Certificate Status Protocol) is a standard protocol in the PKI system used to query in real time whether an SSL certificate has been revoked. When a client (such as a browser) establishes an HTTPS connection, it sends a query to the CA's OCSP server to verify whether the certificate is currently valid.
What is CN OCSP?
CN OCSP specifically refers to OCSP local validation nodes / domestic OCSP resolution services deployed for the Chinese mainland region.
Because the OCSP servers of mainstream CAs are mostly deployed overseas, domestic clients may encounter the following issues when accessing them:
- High latency, which affects HTTPS handshake speed
- Packet loss or inaccessibility, leading to certificate validation failures
- Interference or interception in some network environments
Uses of CN OCSP
By deploying local validation nodes within the Chinese mainland, CN OCSP achieves the following goals:
- Speed up certificate status queries: Domestic users access nearby OCSP nodes, significantly reducing network latency
- Improve access stability: Avoid packet loss and timeout issues caused by cross-border access to overseas OCSP servers
- Prevent misjudgment: Reduce "untrusted" certificate errors caused by network inaccessibility
Currently, brands such as sslTrus and CFCA have deployed OCSP nodes in China, which can effectively guarantee the SSL certificate validation experience for domestic users.