Security for paging messages

An apparatus of a Mobility Management Entity (MME), comprising:

• one or more processors to assign a temporary user equipment (UE) identifier to a UE, derive a dynamic scrambling key in response to the UE releasing a radio resource control (RRC) connection and determine whether a non-access stratum (NAS) security mode control procedure is performed by the UE during the RRC connection, wherein, when the NAS security mode control procedure is performed during the RRC connection, the dynamic scrambling key is derived based on at least a cell identity and a NAS count value used to track a security mode complete message for the NAS security mode control procedure and, when the NAS security mode control procedure is not performed during the RRC connection, the dynamic scrambling key is derived based on at least the cell identity and a NAS count value used to track an initial uplink NAS message for RRC connection establishment;
• and
• a memory to store the dynamic scrambling key and a temporary UE identifier (temporary UE ID) assigned to the UE;
• wherein the one or more processors are to generate a scrambled UE ID derived via scrambling the temporary UE ID with the dynamic scrambling key, and to generate a paging request intended for the UE using the scrambled UE ID.

One or more non-transitory computer readable media having instructions stored thereon that, if executed by a user equipment (UE), result in:

• deriving a dynamic scrambling key in response to the UE releasing a radio resource control (RRC) connection;
• determining whether a non-access stratum (NAS) security mode control procedure is performed during the RRC connection, wherein, when the NAS security mode control procedure is performed during the RRC connection, the dynamic scrambling key is derived based on at least a cell identity and a NAS count value used to track a security mode complete message for the NAS security mode control procedure and, when the NAS security mode control procedure is not performed during the RRC connection, the dynamic scrambling key is derived based on at least the cell identity and a NAS count value used to track an initial uplink NAS message for RRC connection establishment;
• storing the dynamic scrambling key and a temporary UE identifier (temporary UE ID) assigned to the UE;
• monitoring a paging request for a scrambled UE identifier (UE ID);
• and
• determining if the paging request is intended for the UE by unscrambling the scrambled UE ID with the dynamic scrambling key to produce the temporary UE.