Sending a message and a message hash encrypted by the sender’s private key will ensure:

A.
authenticity and integrity.

B.
authenticity and privacy.

C.
integrity and privacy.

D.
privacy and nonrepudiation.

Explanation:
If the sender sends both a message and a message hash encrypted by its private key, then the receiver can
apply the sender’s public key to the hash and get the message hash. The receiver can apply the hashing
algorithm to the message received and generate a hash. By matching the generated hash with the one
received, the receiver is ensured that the message has been sent by the specific sender, i.e., authenticity, and
that the message has not been changed enroute. Authenticity and privacy will be ensured by first using the
sender’s private key and then the receiver’s public key to encrypt the message. Privacy and integrity can be
ensured by using the receiver’s public key to encrypt the message and sending a message hash/digest. Only
nonrepudiation can be ensured by using the sender’s private key to encrypt the message. The sender’s public
key, available to anyone, can decrypt a message; thus, it does not ensure privacy.