**4. Proposed Solution**

We propose a crowd-based mix context scheme which offers location privacy to vehicles in a vehicular network. The scheme comprises two cases based on the vehicle speed, direction, and traffic density. The first case in our proposed scheme is the road intersection or the situation in which vehicles have low speed and traffic congestion on the road. In the second case, vehicles have low speed and fewer neighbors within transmission range. We use a mix context method to hide the actual identity of the vehicle in a crowd. A crowd of vehicles of similar status neighboring vehicles is established where they mix their context and identities to blur the sensitive information of vehicles. Here, context means a vehicles' direction of movement, speed range, and the number of transmission range neighboring vehicles. The proposed scheme block diagram is shown in Figure 4. The vehicle senses the environment to find the number of neighboring vehicles in its range. Based on the road context information, vehicles change pseudonyms to mix it in the crowd of vehicles. Otherwise, the virtual crowd method is used to mix the identities of vehicles. In the first case, there is a higher number of neighboring vehicles in the vicinity, and the simple pseudonym changing process is used, while in the second case, there is a lower

number of neighboring vehicles in the transmission range, so the target vehicle selects neighboring vehicles randomly to exchange pseudonyms with. In both of these cases, there is a need for the protection of location privacy of vehicles. The whole process of the crowdbased mix context procedure is explained with the help of Algorithm 1. *DenThreshold* is the vehicle traffic threshold and *NeigThreshold* is the number of transmission range vehicles in the vicinity of a target vehicle. The high-level flowchart of the mix context scheme is shown in Figure 5.

**Figure 4.** The block diagram of vehicles context mixing.

**Figure 5.** The high-level flow of the mix context method.
