Intelligent Reflective Surface Aided Channel Phase Probing for Physical Layer Key Generation in Transportation Systems

Focusing on the issue of secret key generation for transportation systems and electronic devices in possible less-dynamic channel conditions, this paper proposes an intelligent reflective surface aided channel phase probing scheme (IRS-CPP) for improving physical layer key generation. Specifically, we consider the model that both legitimate nodes first acquire the secret key from the channel phase response by employing channel probing. Then, the passive IRS are utilized to enhance the probing signal by using random phase shifts, which can effectively modify the signal phases. Furthermore, we provide the performance analysis of the proposed scheme in terms of the theoretical key capacity to estimate performance of the scheme. Finally, comprehensive results including the key capacity, key generation rate (KGR), key inconsistency rate (KIR) and key randomness are investigated. Simulation results demonstrate that the proposed scheme can effectively enhance the physical layer key generation performance in the static scenario compared with the benchmark key generation schemes.