Efficient secret key generation scheme of physical layer security communication in ubiquitous wireless networks

Abstract

This paper focuses on high efficiency secret key generation mechanism of physical-layer communication over fading channels in ubiquitous wireless networks. The secret key rate via traditional physical-layer approach could be limited when the wireless propagation channels connecting two sensors change slowly. To generate a high-rate secret key and improve the communication efficiency over quasi-static block fading channels, a novel multi-randomness device-to-device secret key generation strategy and a cooperative communication mechanism aided by relay nodes are proposed. In the proposed schemes, the legitimate members to send random signals rotationally in every coherent time T are set; thus, two legitimate ubiquitous wireless network members, Alice and Bob, can obtain the potential correlated information by exploiting the randomness and the reciprocity of the wireless propagation channels. Considering the reciprocity of wireless channels is variable while the forward channel gain and backward channel gain are correlated in coherent time, a modified secret key generation scheme is proposed via layered coding with theoretical secret key rates derived. The simulation results show that the proposed scheme outperforms traditional approaches with favourable application prospects in ubiquitous wireless communications networks and internet of things.