Question: What protocol is utilized on the reference point Ub between the UE (User Equipment) and the BSF (Bootstrapping Server Function) for mutual authentication and bootstrapping of session keys based on 3GPP AKA infrastructure?
Option 1: TLS (Transport Layer Security)
Option 2: DTLS (Datagram Transport Layer Security)
Option 3: HTTP Digest AKA (Authentication and Key Agreement)
Option 4: IPsec (Internet Protocol Security)
Explanation: The HTTP Digest AKA protocol is used on reference point Ub for mutual authentication between the UE and the BSF, leveraging the 3GPP AKA infrastructure, enabling secure bootstrapping of session keys.