Question: What are the two primary security mechanisms relied upon for BSF-to-UE authentication and establishment of the key Ks in Generic Bootstrapping Architecture (GBA)?
Option 1: Only GSM Security, leveraging the secrecy of the GSM triplet.
Option 2: Solely TLS Security, ensuring confidentiality of transmitted parameters.
Option 3: A combination of both GSM Security (for the GSM triplet) and TLS Security (for confidential transmission of Ks-input parameter).
Option 4: Neither GSM nor TLS Security; instead, relying on an unspecified proprietary method.
Explanation: The correct answer is Option 3 because, as per telecom security principles in GBA, both traditional cellular network security (GSM Security, including protection of Kc within the GSM triplet) and internet-based security protocol (TLS Security, for encrypting the Ks-input parameter during transmission) are utilized, enhancing overall security by requiring an attacker to compromise two distinct mechanisms.