Question: What is the primary purpose of the reference point Ub in a Generic Authentication Architecture (GAA) context, specifically between the User Equipment (UE) and the Bootstrapping Server Function (BSF)?
Option 1: To facilitate direct data transfer between the UE and external applications.
Option 2: To enable the BSF to perform software updates on the UE.
Option 3: To establish a secure tunnel for voice communications.
Option 4: To provide mutual authentication and bootstrap session keys using 2G AKA infrastructure.
Explanation: The correct answer is Option 4 because, as defined by GAA principles, reference point Ub ensures secure communication between the UE and BSF through mutual authentication and bootstrapping session keys based on existing 2G Authentication and Key Agreement (AKA) infrastructure, enhancing security without requiring new key exchange mechanisms.