Cross-region-based authentication method for secure communication of Internet of Vehicles

The invention provides an authentication method based on cross-regional vehicle networking security communication. A system model comprises a vehicle user Vi, a roadside unit RSU and a cloud server CS. The communication process comprises the following steps: S1, in a first area, a vehicle user and a roadside unit RSU1 realize communication through mutual authentication and establishment of a session key; s2, the RSU1 notifies the RSU2 that the vehicle user is about to drive to a second area, and the two parties realize authentication under the assistance of the CS; s3, the RSU2 requests private data about the vehicle user from the CS; and S4, when the vehicle user runs to the second area and communicates with the RSU2, the vehicle user and the RSU2 directly realize mutual authentication and establish a session key. According to the technical scheme, the problems that in the prior art, seamless switching authentication cannot be achieved in a vehicle cross-region mode, and communication smoothness cannot be gu