Complex sentence: OCSP has several advantages over older Certificate Revocation List (CRL)-based certificate revocation-checking approaches; however, it can introduce a significant penalty for certificate authorities who are now required to provide responses to every client of a given certificate in real time.
Split into simpler sentences: OCSP has several advantages over older Certificate Revocation List (CRL)-based certificate revocation-checking approaches. OSCP can introduce a significant penalty for certificate authorities who are now required to provide responses to every client of a given certificate in real time.