Research On Secure Connectivity Aware Routing Protocol For Vehicular Ad Hoc Networks

VANET (Vehicle Ad Hoc Networks) is a kind of MANET (Mobile Ad Hoc Networks), which communicates between vehicles and roadside infrastructures. With the development of economy, the amount of cars has increased rapidly, so the intelligent transportation system is widely used in the fields of MANET application. VANET have some characteristics as follows:the nodes of VANET move fast, network topology changes more rapidly, the nodes are peer-to-peer, self-organization and so on, which determine the VANET is different from other types of MANET. So for the VANET, how to design a new routing protocol guaranteed information transmission timely and reliably is necessary. Generally there are mainly two routing algorithm in MANET, one is topology-based routing algorithm, while in VANET it has a high delay of message transmission and a mass of packet lost; the other is position-based routing algorithm, which is adapt to the scene that network topology changes frequently, so it is more suitable for VANET.The thesis proposes a new secure routing protocol for VANETS—SCAR, which is based on the CAR protocol. The new protocol improved the security of CAR, added authentication mechanism. Based on the TESLA algorithm, the paper proposes a new secure signature algorithm—hcsrTesla, the algorithm uses a self renewal Tesla hash chain algorithm. This algorithm can provide the source authentication, and resist to routing attack. For the SCAR protocol, we made simulation on NS2, written perl program to analysis the trace file of the experiment results, calculated the average end to end latency of packets and the receive ratio of packets. Experiments results show that when routing attack existed, SCAR is immune to source attack, guarantees the correctness of routing, achieves satisfactory packet receive ratio, and maintains the receive ratio of packets at a higher level.The innovation of this paper place mainly in the following three aspects:(1) The paper analyses and compares several VANET secure signature algorithms. TESLA signature algorithm has the advantage that authentication time is short, so it is more suitable for VANET. As hash chain would exhaust in TESLA algorithm, the thesis puts forward a new algorithm based on hash chain self renewal algorithm:hcsrTesla.(2) The paper analyzes the practicality and safety of CAR protocol, because of some shortcoming existed in CAR protocol, the thesis proposes a new secure vehicle ad hoc networks routing protocol SCAR based on the hcsrTesla signature algorithm. The new protocol used source authentication algorithm, which can prevent the black hole attack, etc, besides it also can guarantee the authenticity and integrity of the messages.(3) In this thesis, we simulate CAR routing protocol and SCAR routing protocol with the simulation platform of NS-2, in the Linux system, and compare the performance between them. From the comparision, we made the conclusion that, SCAR protocol provides security for the network routing protocol, and maintains the messages correctly in the transmission process.