Intelligent Reflecting Surface-Assisted Secret Key Generation With Discrete Phase Shifts in Static Environment

Physical layer secret key generation is a promising candidate to achieve one-time-pad encryption approach for the wireless communication system. However, in static environment, rate low due lack of channel time-variation. To solve this problem, letter proposes novel scheme assisted by an intelligent reflecting surface with discrete phase shifts. In scheme, legitimate nodes construct dynamic time-varying rapidly and randomly switching IRS elements. Then, coefficients are used generate key. Based on model, we derive probability distribution coefficient expressions rate. Furthermore, optimize adjusting time phase. Monte Carlo simulation numerical results show that our proposed can update environment.