Embodiments of this disclosure provide techniques for communicating in a wireless communication system. In particular, a user equipment (UE) may receiving a security command message from a base station comprising an indication of an integrity protection algorithm and an indication of an encryption algorithm. The first security command message may trigger a radio resource control (RRC) traffic signaling protection procedure between the UE and the base station. The UE transmits a security command complete message to the base station. The security command complete message may trigger a packet data unit (PDU) session establishment procedure to establish a PDU session between the UE and the base station.