Information Security: Principles and Practices 2nd Edition by Jim Breithaupt, Mark S. Merkow

Exercise 13

A message is said to be digitally signed if sent with which of the following?

A. message digest

B. message digest encrypted with sender’s public key

C. message digest encrypted with sender’s private key

D. message and sender’s digital certificate

Step 1 of 2

Digital signed

Digital signature is a method that is used to check the authenticity of the message. It ensures the recipient that the message has been send from the intended user only. It also makes use of message digest that ensures the integrity of the data.

The message digests are computed using the SHA-1 algorithm which is then encrypted using the private key. This creates a digitally signed message ready to be sent over the network. Therefore, the correct option is.