Applying Intelligent Reflective Surface to Channel Phase Probing in Wireless Secret Key Generation

Abstract Aiming at the problem of secret key generation in the static wireless communication environment, this paper proposes a scheme applying intelligent reflective surface to channel phase probing (IRS-CPP) in wireless secret key generation. Firstly, both legitimate parties utilize OFDM signals for channel probing to obtain the corresponding channel phase response. Secondly, the passive elements in the IRS are used to reflect the probing signal, which can effectively change the signal phases. Finally, the secret key can be obtained after reconciliation and privacy amplification. This scheme makes full use of the reciprocity of the phase response in wireless channels, and applys the IRS elements to change the static environment indirectly. Compared with the existing key generation scheme, the proposed scheme effectively improves the performance of secret key generation in static environments.