Question: What is a mandatory security feature for the reference point Zh between the Bootstrapping Server Function (BSF) and the Home Subscriber Server (HSS), which may be fulfilled by physical or proprietary measures due to their location within the same operator's network?
Option 1: End-to-End Encryption for all User Data
Option 2: Mutual Authentication, Confidentiality, and Integrity
Option 3: Regular Security Audits and Compliance Reporting
Option 4: Mandatory Timestamp Synchronization for All Transactions
Explanation: The correct answer is Option 2 because, according to the requirements for reference point Zh, mutual authentication, confidentiality, and integrity must be provided. This is crucial for securing the communication between the BSF and HSS, especially when exchanging sensitive information like bootstrapping details and subscriber security settings. The fact that these entities are within the same operator's network might allow for physical or proprietary security measures to fulfill this requirement, highlighting the importance of robust security practices even within trusted networks.