Secure Integrated Communications and Sensing Using Physical Layer Key Generation

To establish a secure integrated communications and sensing (ISAC) system, this paper proposes a physical layer key generation (PLKG) scheme coupled to the ISAC characteristics. Firstly, we propose a novel PLKG protocol and formulate a sum secret key rate maximization problem under the sensing accuracy by jointly optimizing the communication and sensing beamforming. To address the complex optimization problems, a proximal policy optimization (PPO)-based reinforcement learning (RL) algorithm is proposed. Simulation results demonstrate the effectiveness and superiority of the proposed PPO-based RL algorithm compared to the benchmark schemes.