Physical Layer Security Scheme With AoI-Awareness for Industrial IoT Based on Covert Communications

Dear Editor, Industrial Internet of things (IIoT) is a typical application of cyber-physical system (CPS). In the IIoT, wireless communication is an inevitable trend to replace the deployment-limited wired transmission for cases with large-scale and mobile devices. However, wire-less communication gives rise to critical issues related to physical security, such as malicious detections and attacks [1]. To ensure secure transmission of legitimate data, covert communications are a promising physical-layer technology that shields transmitted content through low-detection-probability communications, and the main idea of covert communications is to interfere with attackers and increase their detection error rate r21.