Key Agreement Phase for New Vehicle Joining Sample Clauses

Key Agreement Phase for New Vehicle Joining. After a vehicle get authenticated by RSU, its identity and Ki get trusted, then it would have the ability to establish common session key with RSU and other authenticated vehicles. In this paper, we design a new tree-based key agreement algorithm to compute the common session key, which only requires the behaviour of the RSU is honest. It is noteworthy that the original tree-based key agreement algorithm [16] that inspired us is not suitable for VANETs because of the reasons described in Section I&II. To describe the key agreement algorithm for new vehicle joining, we denote the vehicles that have joined key agreement process as ordered sequence {V1, V2, ..., Vn−1} where V1 is the first joined vehicle and Vn−1 is the last joined vehicle, and the new vehicle is Vn. It is noteworthy that the indexes i = 1, 2, ..., n of Vi are just used to mark the order of vehicle joining and will be changed when one of vehicles leaves. The method used to calculate the common session key is as shown follows.