A Lightweight Combined Physical Layer Encryption and Authentication Scheme for Industrial Internet of Things

The Industrial Internet of Things (IIoT) greatly facilitates industrial production and economic development. However, it has more vulnerabilities facing the security issues introduced by the openness of wireless communications. Hence, a lightweight combined physical layer encryption and authentication (PLEA) scheme is proposed in this paper to protect resource-constrained IIoT devices. In the proposed PLEA scheme, quadrature phase shift keying (QPSK) modulation is adopted and the quadrant feature is extracted along with the shared key to generate a dynamic encrypting sequence and a tag. Then, physical layer encryption (PLE) and tag-embedding are carried out by phase reverse and power assignment according to the encrypting sequence and the tag, correspondingly. At the receiver, the same quadrant feature is extracted from the received signals and then is used to regenerate the tag and the decrypting sequence in order to execute physical layer authentication (PLA) and decryption. The error rates of the signal detection and tag detection are given, then the probability of detection and false alarm probability of the proposed PLA scheme are also obtained. In addition, the unified average changing intensity is defined and derived to analyze the performance of the PLE. Finally, computer simulation results show that the proposed scheme could provide effective security protection for IIoT.