Design and Simulation Verification of a Dynamic Key Agreement Mechanism for Intelligent Connected Vehicles Based on Sm9

To address the security risks of traditional static encryption mechanisms in V2X communications, this paper proposes a lightweight dynamic key agreement mechanism that integrates vehicle dynamic status with SM9 identity-based cryptography. By employing multi-factor key generation and a distributed trust model, the proposed scheme achieves one-time-one-key secure communication. Experiments based on Python simulations verify the efficiency of key generation and the ability to resist replay attacks. The results demonstrate the feasibility of the mechanism in in-vehicle scenarios.