If an attacker changes the Tag (MAC) and ciphertext while using a message authentication code (MAC), what happens? Explain why this attack will fail as the recipient would recognize a changed tag or ciphertext?

How are different attacks on message authentication prevented and how are they prevented?

Explain the challenge-response authentication mechanism and how it works. It is not immediately clear what makes it more secure than a normal password-based solution.

The attacker uses the MAC to try to alter the Tag (the encrypted message) (message authentication code). Exactly what are the potential outcomes if I do this? If this attack succeeds, the target will always be able to spot a tampered Tag or ciphertext.

When it comes to security, what's the difference between verifying the identity of a sender and a recipient?

Either the PAP or CHAP protocol may be used to set up PPP authentication. Which approach provides the best possible degree of protection? It is necessary for you to provide an explanation for the answer you provided.

Attackers use MACs to modify the Tag (ciphertext) and MAC (message authentication code). What if I did this? This attack will always reveal a changed Tag or ciphertext to the receiver.

Changing either the tag or the MAC will allow an adversary to decode the ciphertext (message authentication code). Can you see any potential problems with this plan? If this attack is effective, the target may be able to decipher a ciphertext that has been altered from the original Tag.

In a two-factor authentication system using both private and public keys, who should have access to the private key?

What happens if an attacker attempts to alter the Tag (the MAC) and the ciphertext when a message authentication code (MAC) is being used? Describe why a successful attack like this would never be possible since the recipient might detect a changed tag or ciphertext.