Question: What is the consequence of an MME not including RAND and AUTS in the authentication data request to the HSS during a re-synchronization procedure, when the synchronization failure was due to a problem with the sequence number SQNHE in the HSS?
Option 1: The HSS will update SQNHE based on AUTS, ensuring subsequent authentications succeed.
Option 2: A new authentication vector (AV) will be returned, leading to successful authentication between MME and UE regardless of the failure cause.
Option 3: The subscriber may be temporarily unable to authenticate, but a retry will resolve the issue.
Option 4: An update of SQNHE based on AUTS will not occur in the HSS, potentially leading to permanent authentication failures for the subscriber.
Explanation: This scenario highlights a critical security implication: omitting RAND and AUTS in an authentication request during re-synchronization due to an SQNHE issue in the HSS can lead to permanent authentication failures for the subscriber, as the sequence number won't be updated correctly. Including RAND and AUTS is crucial to prevent such security-relevant failures.