The Research On Privacy Protection Technology In Vehicular Ad-hoc Network

The Vehicular Ad-hoc Network is an important application of the traditional Mobile Ad-hoc Network in the field of transportation.It is also an important part of the Intelligent Transportation System.It is mainly composed of Onboard Unit,Roadside Unit,Register Authority and Service Provider.The vehicle can obtain surrounding traffic conditions by the Vehicular Ad-hoc Network so that it can make more efficient and accurate trip route,and improve the travel efficiency.The relevant departments can also use the Vehicular Ad-hoc Network to monitor the traffic flow and deal with accidents more quickly when traffic accidents occur and so on.In addition,vehicles could access the Internet through the Vehicular Ad-hoc Network to obtain Location Based Services by service providers and so on.Although the Vehicular Ad-hoc Network can bring great convenience to people's life,if the problem of privacy protection can not be solved,the deployment and operation of the Vehicular Ad-hoc Network could be hindered.The Vehicular Ad-hoc Network is developed on the basis of the traditional Mobile Ad-hoc Network and it also has its own characteristics.Therefore,the Vehicular Ad-hoc Network can easily lead to the privacy disclosure of vehicle users.For example,if the path of a vehicle is tracked maliciously,there will be a great possibility to infer the personal privacy of the vehicle user.Therefore,this thesis studies the problem of privacy protection in the Vehicular Ad-hoc Network.The main contents are as follows:1.This thesis introduces the main composition and characteristics of the Vehicular Ad-hoc Network,and summarizes the current status of the research on the privacy protection of the Vehicular Ad-hoc Network.2.This thesis proposes a changing pseudonym scheme which is based on virtual vehicles.The virtual vehicles are represented by different pseudonyms.This kind of vehicles are released from Register Authority to the virtual vehicle generator.The probability of the target vehicle to select the attacker is reduced by increasing the virtual vehicles,and the probability of successful tracking in the pseudonym changing is reduced.Then the simulation experiment is carried out on this scheme.The experimental results show that the scheme reduces the probability of successful tracking of the target vehicle.3.A location privacy protection scheme which is based on path confusion and virtual vehicles is proposed.In the existing scheme,the target vehicle collects beacon messages of nearby vehicles to get location data before sending Location Based Service requests.This scheme reduces the probability of trajectory being leaked by sending the location data of the target vehicle and nearby vehicles simultaneously.However,the number of vehicles around the target vehicle may fewer before the Location Based Service request is put forward.This will reduce the degree of confusion of the target vehicle trajectory,and the degree of privacy protection of the target vehicle will also be reduced.Therefore,the target vehicle can collect more available location data by increasing the virtual vehicles.The simulation experiment is carried out on this scheme.The results show that this scheme can improve the number of effective location data which are collected by the target vehicle and the degree of location privacy of the target vehicle.