Question: In a GBA security context on a USIM, when updating EFGBANL with a new NAF_ID and B-TID, if no empty record is available, how does the USIM determine which existing record to overwrite?
Option 1: The USIM overwrites the record associated with the oldest stored Ks_int_NAF key.
Option 2: The USIM constructs a list of record numbers, prioritizing the last used or derived Ks_int_NAF, and overwrites the last record in this list.
Option 3: The USIM randomly selects an existing record to ensure security through unpredictability.
Option 4: The USIM aborts the operation and returns a '6985' status word indicating 'Conditions of use not satisfied'.
Explanation: This is correct because, according to the specified behavior for handling no available empty records in EFGBANL updates within the GBA security context, the USIM utilizes a methodical approach. It creates a list where the most recently utilized or derived Ks_int_NAF key's record number is first, and then overwrites the last (least recently used) record in this constructed list. This ensures efficient management of storage while preserving the integrity of more recently used keys.