A High Consistency Wireless Key Generation Scheme for Vehicular Communication Based on Wiener Filter Extrapolation

Secret key generation from wireless channel is an emerging technology for communication network security, which exploits the reciprocity and time variability of wireless channels to generate symmetrical keys between the communication parties. Compared to the existing asymmetric key distribution methods, secret key generation from wireless channel has low complexity and high security, making it especially suitable for distributed networks. In vehicular communications, the reciprocity of wireless channel is degraded due to the movement of vehicular. This paper proposes a high consistency wireless key generation scheme for vehicular communication, especially applied to LTE-V2X (LTE vehicle to everything) systems. A channel reciprocity enhancement method is designed based on Wiener filter extrapolation, which can efficiently reduce the mismatch between the channels at the receiver and significantly reduce key disagreement rate. A real experimental system based on vehicle and universal software radio peripheral (USRP) platform is setup to verify the secret key generation in LTE-V2X systems. The effectiveness of the proposed method is verified in simulations and extensive practical tests.