Abstract: A method performed by a first terminal performing vehicle-to-everything (V2X) communication with a second terminal via one or more PC5 unicast links in a wireless communication system is provided. The method may include: receiving, from a core network entity, information on one or more security policies respectively corresponding to the one or more PC5 unicast links, wherein each of the one or more PC5 unicast links is associated with one or more V2X services; transmitting, to the second terminal, a direct communication request message including the one or more security policies for initiating the V2X communication; and in case that the transmitted direct communication request message is accepted by the second terminal, activating a security of each of the one or more PC5 unicast links based on the received information on the one or more security policies.

Abstract: A method performed by a first terminal performing vehicle-to-everything (V2X) communication with a second terminal via one or more PC5 unicast links in a wireless communication system is provided. The method may include: receiving, from a core network entity, information on one or more security policies respectively corresponding to the one or more PC5 unicast links, wherein each of the one or more PC5 unicast links is associated with one or more V2X services; transmitting, to the second terminal, a direct communication request message including the one or more security policies for initiating the V2X communication; and in case that the transmitted direct communication request message is accepted by the second terminal, activating a security of each of the one or more PC5 unicast links based on the received information on the one or more security policies.

Abstract: Methods and systems for identifying AUSF and accessing related keys in 5G ProSe. The AUSF corresponding to a remote UE is identified by an AMF based on routing indicator or SKI. The AUSF is capable of key management of ProSe UE-to-Network relay communication. The AUSF authorizes the remote UE to access a 5G core network through one or more UE-to-network relays. The authorization of the remote UE is performed based on a SUPI corresponding to the remote UE. The SUPI is obtained from a UDM. Once the remote UE is authorized, the AUSF can derive keys that enable the remote UE to access the 5G core network through the one or more UE-to-network relays. The keys derived by the AUSF 803 can be referred to as authentication keys. The derived keys include REAR key, KNR_ProSe, KD, and KNRP.

Abstract: A method performed by a first terminal performing vehicle-to-everything (V2X) communication with a second terminal via one or more PC5 unicast links in a wireless communication system is provided. The method may include: receiving, from a core network entity, information on one or more security policies respectively corresponding to the one or more PC5 unicast links, wherein each of the one or more PC5 unicast links is associated with one or more V2X services; transmitting, to the second terminal, a direct communication request message including the one or more security policies for initiating the V2X communication; and in case that the transmitted direct communication request message is accepted by the second terminal, activating a security of each of the one or more PC5 unicast links based on the received information on the one or more security policies.