Question: What is the primary security requirement for the optional reference point Zh' between the Bootstrapping Server Function (BSF) and the Home Location Register (HLR), as per Generic Authentication Architecture specifications?
Option 1: Mutual authentication, confidentiality, and integrity, which may be fulfilled by physical or proprietary measures since both entities are within the same operator's network.
Option 2: End-to-end encryption for all signaling messages with a mandatory public key infrastructure (PKI) setup.
Option 3: Regular security audits and compliance reporting to ensure the trustworthiness of the BSF and HLR.
Option 4: Mandatory implementation of an additional, external firewall between the BSF and HLR.
Explanation: The correct answer is Option 1 because, according to the specifications for reference point Zh', mutual authentication, confidentiality, and integrity are required. Notably, these security measures can be achieved through physical or proprietary means due to both the BSF and HLR being located within the same operator's network, highlighting a balance between security and operational simplicity.