Question: What are the primary purposes of the Zn reference point in the Generic Authentication Architecture (GAA) and Generic Bootstrapping Architecture (GBA)?
Option 1: To fetch key material agreed during a previous protocol run from the BSF to the NAF, and to retrieve application-specific user security settings from the BSF if requested by the NAF.
Option 2: To establish a secure connection between the UE and the BSF for initial bootstrapping, and to manage subscription updates.
Option 3: To facilitate direct communication between the User Equipment (UE) and the Network Application Function (NAF) for authentication bypass.
Option 4: To synchronize security protocols between different Network Application Functions (NAFs) within a single domain.
Explanation: The correct answer, Option 1, accurately reflects the dual purpose of the Zn reference point as defined in the context of GAA and GBA: firstly, to retrieve key material previously established for continuity of security context, and secondly, to obtain specific user security settings on demand from the Bootstrapping Server Function (BSF) for tailored application security.