Question: What security measures are mandated for signaling over the S14 reference point between UE (User Equipment) and ANDSF (Access Network Discovery and Selection Function), according to 3GPP security aspects for non-3GPP accesses?
Option 1: Mutual authentication between UE and ANDSF, with optional integrity protection.
Option 2: Mutual authentication, authorization verification of ANDSF by UE, integrity protection, confidentiality protection, and replay attack protection.
Option 3: Only confidentiality protection and mutual authentication, without specific measures against replay attacks.
Option 4: Integrity protection and confidentiality protection, but no requirement for mutual authentication or authorization verification.
Explanation: This option correctly encompasses all specified security requirements: Mutual Authentication (verifying both UE and ANDSF identities), Authorization Verification (confirming ANDSF's legitimacy), Integrity Protection (safeguarding against unauthorized data modifications), Confidentiality Protection (encrypting signaling to prevent eavesdropping), and Replay Attack Protection (preventing malicious reuse of previously sent messages).