Encrypting the data in transit on the wired network significantly enhances security, as it renders intercepted traffic unreadable and useless to an attacker without the proper decryption key. Changing default passwords does not prevent traffic interception, although it is a basic security practice. Implementing a firewall helps regulate traffic based on security rules but does not directly prevent data interception. Disabling unused services minimizes potential exploit vectors but would not prevent an attacker from capturing traffic that is already allowed on the network.