Research On Key Technology Of Wireless Ad Hoc Network Security

Ad hoc networks need neither infrastructure nor central control. And it is easy to extend, suffers little from natural disasters. Every two nodes can communicate with each other if only they are in each’s range. But while it is convenient, it is also vulnerable. The possible attacks include interception, modification or fabrication. As Ad hoc networks are being used more and more widely, its security is becoming more and more important.Considering the weaknesss in nowadays’ wireless networks, this paper foucs on the fields of security architecture, secure IP protocol, delaunay triangulation and key exchanging. And this paper develops a secure prototype system based on all the research results. The main contributions of this paper are the followings.First, this paper put forward a new cluster based security architecture. Compared to already existed security architecures, the advantage of the new one lies on the follows.(1) Consided the condition that the cluster head is captured. And ensured the security of the whole system even when the cluster head is captured or both the cluster head and the backup cluster head are captured.(2) Designed different schemes for cluster key refersh under different conditions, which ensures the security of the cluster key.The proposed security architecture mainly consist of the following process: initial cluster generation, private key threshold share, public key generation, schemes for cluster head change, new node’s login process, certificate generation for new node, verify of certificate and refreshing of cluster keys. We then make a secure analysis in three directions: security of network private key, security of cluster key and security of transmission. At last we do experiments with NS3. And both the analysis and the experiments say that the proposed security architecture is safely and efficiently, and it’s robust under different conditions.Second, this paper proposes a secure IP protocol, called SIP, which adds a new layer between the MAC layer and the original IP layer. When a packet is received, it will first be throwed to the SIP function to do decryption, and then back to the IP layer. And when a packet is to be sending out, it will also be throwed to the SIP function first to do encryption. We make both theoretical and experimental analysis of SIP followed. The results say that SIP is quit suitable for Mobile Ad Hoc networks.Third, this paper presents a new algorithm for constructing Delaunay Triangulation which is very efficient. This is because we develop a new method to find the triangle that the newly introduced point falls in. Later we use this new algorithm to simply contour lines while preserving topological coherence. And the result says that compared to other algorithms, our algorithm is more efficiently while it is still comprehensible.Fourth, this paper proposes an improved version of Aydos’ s protocol, which uses the restraint of RTT. The new protocol can resist two types of MITM attack that presented by Mangipudi and Liu. It can even resist the strengthened MITM attack in which the attacker has infinite computing resource. We then analyse the new protocol both theoretical and experimental.Fifth, this paper develops a secure wireless ad hoc network prototype system, which is called SWLAN. The SWLAN system consists of multi SWLAN devices. And all the devices automatic set up an ad hoc network. They overall form a secure wireless network.