Research On Privacy-preservation In Vehicular Ad Hoc Networks

Vehicular Ad hoc Network(VANET),which is aimed at providing people safer and more comfortable driving environment, is not only a new type of multi-hop mobile wireless communication network, but also a particular application of mobile ad hoc network(MANET) in the domain of transportation. Thanks to the rapid development of wireless ad hoc network, automotive embedded computing as well as various automotive sensor technologies, VANET is also becoming the darling of the wireless network research field with speedy development in recent years.As an important part of the intelligent transportation system ITS, VANET requires vehicles communicate with each other by a wireless communication module embedded in themselves, and also share the road conditions and other related information in a timely manner in order to enhance the overall driving environment and drivers’ ability of perception and prediction. At the same time, drivers can predict the potential dangerous signals and avoid the road traffic congestion in time, thus provide a secure safe driving environment.However, it is easier for vehicles in VANET to expose their identities and running tracks and then leave criminals an opportunity to exploit the vital informations due to the regular vehical movements, lots of information sharing and any other issues. On the other hand, the traditional privacy protection mechanisms applied in MANET, with their limitations, can not directly be a good fit for VANET for the reason of the high-speed topology changes, a large number of communication channels exposure and private information sharing in VANET.Considering the security and privacy issues in VANET, this paper has done the following work:Firstly, the vehicle nodes in VANET has the characteristcs of high-speed mobility and trajectory of regularity. Based on the Proxy Mobile IPv6(PMIPv6) protocol framework, all the entities are managed by hierachicals and domains. Each mobile access gateway MAG in the domain of PMIPv6 is responsible for issuing the relevant information such as group private keys for vehicle nodes in a localized manner. An efficient privacy-preserving authentication scheme is proposed, in which group signature and identity-based signcryption are exploited, the vehicles can regularly apply and update their private keys from the key management center by signcryption, and then they can sign and send messages on behalf of the group, which can preserve the users’ privacy.Secondly, traditional authentication and privacy protection mechanisms based on group signature suffered from a longer calculation delay and other issues because of CRL checking and signature verification process. To solve this problem, this paper presents a batch message authentication algorithms, and use HMAC check to replace CRL checking before batch certification, which can not only ensure message integrity and legitimacy, but also make the verification time not increase along with the increasing amount of the messages. Meanwhile, in order to reduce the authentication burden brought from the safety related messages of vehicle, we also proposed a scheme in which vehicles can cooperate with each other to authenticate messages, so that each vehicle node only need to select a small number of messages for batch verification, and this greatly improves the efficiency of message verification.