A Shared Secret Key Generation between Vehicle and Roadside Based Preprocessing Method

A secure communication in vehicle-to-roadside (V2R) to protect any possibility of cyberattacks must be considered, since V2R communication allows every vehicle including adversaries to freely communicate with roadside units (RSUs). In this paper, we propose a shared secret key generation extracted from received signal strength (RSS) in V2R communication. We used polynomial interpolation as a preprocessing method to improve RSS correlation between vehicle and RSU. It has low computation time with improving correlation up to 0.9. Then, bits key stream are determined by quantization process and any bit error is repaired by BCH error code correction. The number of keys extracted from bits key stream is about 11 keys. We confirm that all processes consume about 11 seconds, and additional time is about 7 to 9 seconds for channel probing in collecting RSS values on both vehicle and RSU with ping interval time 10 ms, 15 ms or 20 ms.