Cross-domain certificateless authenticated group key agreement protocol for 5G network slicings

Network slicing technology is a core part of 5G network, which enables users to access the suitable network on demand and increases the flexibility of network resources through appropriate network configuration. However, the group users in dynamic 5G network slices face communication security threats (impersonation attack, network monitoring, identity leakage, etc.). Group key agreement (GKA) protocol can be used to ensure the security of communication for group users. However, most GKA protocols do not consider cross-domain environment, or use the same cryptographic system parameters between all communication nodes in cross-domain environment. This study presents a cross-domain certificateless authenticated GKA protocol for 5G network slicings supporting dynamic group users management. This new scheme only needs one-round communication and allows group users from different network domains with different cryptographic system parameters to agree on a group session key in common. The proposed scheme not only can provide authenticated key agreement security, mutual authentication, perfect forward secrecy, user anonymity and partial private key transmission security, but also is able to withstand the impersonation, replay and known temporary key attacks. As compared with existing three certificateless group key agreement protocols, our proposed scheme has less computation time, and the communication overhead of low-power group user in our proposed is reduced by at least 36%.