Which of the following ensures confidentiality of information sent over the internet?

Which of the following ensures confidentiality of information sent over the internet?

A.
Digital signature

B.
Digital certificate

C.
Online Certificate Status Protocol

D.
Private key cryptosystem

Explanation:
Confidentiality is assured by a private key cryptosystem. Digital signatures assure data integrity, authentication and nonrepudiation , but not confidentially. A digital certificate is a certificate that uses a digital signature to bind together a public key with an identity; therefore, it does not address confidentiality. Online Certificate Status Protocol (OCSP) is an Internet protocol used for obtaining the revocation status of a digital certificate.