Research On Privacy Protection In Vehicular Ad-hoc Network

Vehicular ad hoc networks is a kind of mobile ad hoc network, which is formed through the communication between vehicles and vehicles or vehicles and roadside infrastructure. The network can provide services, such as delivering auxiliary driving information, Internet access and the corresponding entertainment information and so on. However, VANET improves traffic efficiency and ride environment, but also brings a lot of privacy threats. Owning to vulnerabilities and openness of the wireless networks, Vehicular ad-hoc networks(VANET) is vulnerable to be attack, such as, eavesdropping, tampering, forgery attack, Dos attack, ect. Therefore VANET must meet authentication, integrity, non-repudiation and other security requirements, at the same time, it also should preserve the users’ privacy. When controversial message appears, it should be able to track the true identity of the vehicle and give the appropriate punishment to the vehicular. Therefore, it is necessary to implement conditional anonymous authentication.In summary, VANET need to implement a conditional anonymous authentication protocol. But the general wireless network security protocol does not apply to car network. Compared with the traditional wireless network, VANET has many characteristics, such as multi node, high mobility, variable network topology, unstable wireless signal, powerful computing power and huge storage space. So it is necessary to design a special security protocol for the vehicle network(such as authentication speed, low transport cost, etc.), which ensures the normal operation of the vehicle network.This paper has carried on the preliminary research and exploration on distributed anonymous authentication, the batch anonymous authentication resisting collusion attack, the privacy protection of the identity and position during the navigation service and the data download are proposed as follows:1) Efficient distributed authentication scheme based on controllable privacy inVANET is proposed. The scheme constructs pseudonyms by using double hashchains. Moreover, the user can update multiple partial private keys by a certificate,which reduces the burden of trust authority(TA) and roadside unit(RSU). Once adispute occurs on a safe message, TA can distinguish whether the signature wasforged by the RSU according to the vehicle’s signature again to the message. Thisway can solve the problem of message released non-repudiation in the distributedenvironment. Performance evaluation shows that the computation overhead and transmission overhead of the private key distribution, signature and verification are superior to the existing research results.2) A batch verification scheme defensing collusive attack in VANET is proposed. The scheme uses aggregate signature to achieve batch verification; uses pseudonym-based private key to sign the message by which can prevent RSU vehicle conspiracy to forgery message effectively. Compared with b-SPECS+, Performance evaluation shows that the proposed scheme not only has the characteristics of bSPECS+, but also has a higher rate than other schemes in the message verification.3) Data fragmentation download service of security and privacy protection based on RSU in VANET is proposed. The scheme collect useful traffic information by RSU, and then generate navigation path according to the vehicle’s anonymous Navigation Certificate. In the running course of the vehicle access to services navigation service number, at the same time segment files are sent to each RSU according to the vehicle path in advance. The vehicle passes the RSU, can achieve large file anonymous download service. Security analysis shows that the proposed scheme can obtain the service without revealing the identity and track.