Digi-CA™ the complete Certificate Authority [CA] system
OCSP Gateway

The OCSP Gateway [OCSPG] Service Module is intended to provide digital
Online Certificate Status Protocol [OCSP] network based services in compliance with RFC 2560 standard, X.509 Internet Public Key Infrastructure Online Certificate Status Protocol - OCSP.

The OCSP is an Internet protocol used for obtaining the revocation status of an X.509 digital public key certificate. It was created as an alternative to Certificate Revocation Lists [CRL], specifically addressing certain problems associated with using CRLs in a public key infrastructure [PKI].