When using a digital signature, the message digest is computed:

A.
only by the sender.

B.
only by the receiver.

C.
by both the sender and the receiver.

D.
by the certificate authority (CA).

Explanation:
A digital signature is an electronic identification of a person or entity. It is created by using asymmetric
encryption. To verify integrity of data, the sender uses a cryptographic hashing algorithm against the entire
message to create a message digest to be sent along with the message. Upon receipt of the message, the
receiver will recompute the hash using the same algorithm and compare results with what was sent to ensure
the integrity of the message.