Final answer:
The Online Certificate Status Protocol (OCSP) was developed to improve the efficiency and reliability of certificate validity checks in large environments by providing a more streamlined, real-time validation method compared to Certificate Revocation Lists.
Step-by-step explanation:
The technology that was developed to help improve the efficiency and reliability of checking the validity status of certificates in large, complex environments is the Online Certificate Status Protocol (OCSP). OCSP provides a more efficient mechanism for checking whether a digital certificate is valid or has been revoked, as opposed to relying on the traditional method which utilizes Certificate Revocation Lists (CRLs). OCSP allows applications to query a certificate authority (CA) in real-time to get the revocation status of a specific certificate, thereby streamlining validation and reducing the network load associated with downloading potentially large CRL files.