*9.3. Computation Overhead*

The vehicle computation time for the pseudonyms changing process is analyzed in this section. Figure 20 shows the average computation time of the proposed scheme CMC using number of neighbors in the transmission range. A higher number of transmission range neighbors will take more time to compute the pseudonyms changing process as compared to lower transmission range neighbors. At the start of the simulation, there is a lower number of transmission range neighbors and a lower computation burden on the vehicles for the pseudonym changing process. The proposed scheme's average computation cost is compared with TAPCS [25] and IndMZ [24], as in Figure 21. The CMC creates a lower computation overhead than existing schemes. This is because of the utilization of road context information and pseudonym changing process for vehicle anonymisation. IndMZ scheme produces a much higher computation cost due to the generation of fake pseudonyms in larger quantities. The TAPCS generates a lower cost of computation than IndMZ by utilizing the vehicle traffic conditions in the road environment, although the proposed scheme CMC has a lower computation overhead as compared with the existing scheme. However, this overhead can be reduced further to optimize the computation and communication time of vehicles by applying a privacy scheme.

**Figure 20.** CMC computation overhead for the pseudonyms' changing process.

**Figure 21.** Average computation cost with a various number of vehicles.
