We disclose various embodiments that enable a mobile terminal to authenticate a base station before the mobile terminal proceeds to attach to the corresponding network and/or camp on the corresponding cell, e.g., during the initial network selection and attachment or during an idle mode. In an example embodiment, the authentication processing includes the mobile terminal generating and sending to a candidate base station a system query with a nonce. The candidate base station is deemed to be authentic only if the acknowledgement generated and transmitted in response to the system query includes a copy of the nonce properly signed by a digital signature generated using one or more security keys. In some embodiments, the system query may also include a request for GPS coordinates and/or selected system information signed using a digital signature, which the mobile terminal may beneficially use to further strengthen the protection against a spoofing attack.