Question: During an X2/S1 handover in a 3GPP network, what security algorithms can a target eNB select for integrity and confidentiality protection if it receives UE EPS security capability with EIA0 and EEA0 from the source eNB?
Option 1: Any supported integrity and confidentiality algorithms (e.g., EIA1, EIA2, EEA1, EEA2, etc.)
Option 2: Only EIA0 for both integrity and confidentiality protection
Option 3: Either EIA0 or EEA0 for both integrity and confidentiality protection, interchangeably
Option 4: EIA0 for integrity protection and EEA0 for confidentiality protection exclusively
Explanation: When a target eNB receives UE EPS security capability with EIA0 (a NULL integrity algorithm) and EEA0 (a NULL confidentiality algorithm), it is restricted to selecting these specific algorithms for handover, choosing EIA0 for signaling integrity and EEA0 for data confidentiality, typically in emergency or low-security contexts.