$[$CLO$-6]$ An Infrared token is used in a parking garage to open the barrier. The protocol below shows the communication between the

token and the garage barrier:

$TG$:$S,\{S,N\}KT$

The token sends the garage barrier a serial number and a blob containing the serial number and a nonce encrypted by KT the key shared

between the token and the garage barrier. The garage barrier verifies the user by decrypting the message and checks that the serial

number transmitted is similar to the one in the ciphertext. Is the protocol vulnerable?

Selected Answer: Yes