שאלה | In response to the security issue where an attacker could intercept and retransmit the same encrypted "Open" command to repeatedly open the gate, the developers modified the system by adding a Message Authentication Code (MAC). Now, the application encrypts the "Open" command using AES with the shared symmetric key K1, and generates a MAC using a second key K2 .The encrypted command (ciphertext) and the MAC are sent to the server together Does this modification prevent the attacker from using the intercepted ciphertext to open the gate?

In response to the security issue where an attacker could intercept and retransmit the same encrypted "Open" command to repeatedly open the gate, the developers modified the system by adding a Message Authentication Code (MAC). Now, the application encrypts the "Open" command using AES with the shared symmetric key K1, and generates a MAC using a second key K2 .The encrypted command (ciphertext) and the MAC are sent to the server together Does this modification prevent the attacker from using the intercepted ciphertext to open the gate?

		Yes, the addition of the MAC secures the system by ensuring the integrity and authenticity of the command.
		Yes, because the MAC ensures that the message was not altered in transit
		No, because the attacker can still intercept both the ciphertext and MAC, and retransmit them to open the gate, as the MAC does not change for the same command.
		No, because the MAC cannot prevent the attacker from guessing the correct key.

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