A New Radio Access Stratum Security Architecture Supporting Dynamic 5G Radio Access Networks

In this paper we introduce a new, flexible radio access stratum security architecture for 5G mobile networks that supports a dynamic, flexible radio access network with multiple different security termination points for the control and user plane communication between a mobile device and the network. We describe key refreshing methods that allow to refresh user plane keys for individual radio legs independently of the respective control plane keys and of user plane keys used on other radio legs in the same access stratum connectivity session. We describe procedures allowing the flexible relocation of security termination points as well as supporting multiconnectivity over multiple radio access technologies. We also discuss how the proposed key hierarchy and security procedures are applicable in the context of multiple network slices running on a common infrastructure. We conclude that our new radio access stratum security architecture is well suited to support the capability of dynamic, flexible allocation and optimization of radio access network functions that we consider to be an important property of future 5G radio access networks. Keywords—5G radio access network, access stratum security, key hierarchy, security negotiation, key refreshing, 5G NORMA