On the Application of Key-Based Physical Layer Security in 5G Heterogeneous Networks

Concern for 5G security is driving interest in additional methods capable of exchanging secure information. This paper introduces a scheme for extending 5G with Physical Layer Security, an emerging Open Systems Interconnect Layer-1 security area that achieves perfect secrecy data transmission. The foundations for a Stochastic Geometry approach to Key based Physical Layer Security are established for 5G Heterogeneous Networks. This work also introduces realistic Time Division Duplex algorithms integrated with 5G-OFDM reference signals that enable the exchange of shared, private information. The resulting Physical Layer Security protocols map random secret key bits to precoders in a codebook through a Precoder Matrix Index. Analysis is presented for Key Bit Error rates under realistic stochastic geometry frameworks in MIMO Rayleigh fading, under various base station densities, interference profiles, and configurations. A Key Bit Error Rate of 1% and 3% for both 1 and 2 bit code books is achieved with a network base station density of 0.01 km−2 and 0.1 km−2respectively. The proffered Layer-1 protocols, which operate independently of existing higher layer network and transport layer security, can lead to significantly improved 5G security.