A Secure Wireless Transmission Scheme: Reconstructing Spatial Radio Environment Map and Redirecting Electromagnetic Signal Propagation Path

Ensuring secure wireless transmission remains a critical challenge because of the presence of malicious and active eavesdroppers (Eves). To address this issue, a novel two-phase secure transmission scheme is proposed in this paper by reconstructing a spatial radio environment map (REM) and redirecting the electromagnetic signal propagation path (ESPP). In the first phase, distributed nodes sense the electromagnetic signal data and then report it to the access point (AP). The AP can then reconstruct a high-precision spatial REM to detect the target Eve, as Eve corresponds to a suspicious signal source on the REM. In the second phase, a reconfigurable intelligent surface (RIS) is activated to redirect the ESPP and maximize the achievable secrecy rate. The simulation results demonstrate that both the reconstruction of the REM and the redirection of the ESPP outperform the corresponding baseline methods. As one of the contributions, an innovative index is presented to evaluate the effect of reconstruction, which is called the similarity score (SS). Furthermore, the REM’s dynamic refresh capability ensures robust tracking of mobile eavesdroppers. Another contribution is that this study provided a novel approach for the physical layer security of 5G and/or 6G communications in dynamic urban scenarios.