User-Independent Randomized Pilot Activation for Secure Key Generation

In this paper, we propose a novel physical-layer secret key generation (SKG), which randomly activates a pilot sequence during the channel probing phase. Each legitimate user interpolates the received signals to recover the full channel state information (CSI). Due to the random reduction of the pilot sequence, the proposed scheme can degrade the eavesdropping performance regardless of the correlation between legitimate users and eavesdroppers, thereby improving the secret key capacity (SKC). Furthermore, low power consumption during the channel probing phase can be achieved. Our simulation results demonstrate that the proposed scheme exhibits superior performance in the presence of eavesdroppers.