Research On Some Key Issues Of Routing And Security In The Mobile Ad Hoc Network

A mobile ad hoc network (MANET) is a special wireless network that is self-organized by mobile nodes communicating with each other using distributed protocols. MANET can work in absence of fixed infrastructures, such as base stations. When wired networks are not available, e.g. in battlefield communication and emergent search-and-rescue scenarios, MANET provide a feasible way for communication and information access. Along with the growing civil and military applications of mobile ad hoc network, the security issue of the network receives increasing attention. Security is essential for MANET, and it is also one of the hot areas in MANET research nowadays. Currently, the major sub-areas of security research include secure routing, secure group communications, authentication and key management etc.Aming at the problem of network overhead and delay caused by frequent change of MANET network topology, which brings too many route discovery procedures, this paper propose a node disjoint multipath routing protocol NDM (Node Disjoint Multipath), which is based on AODV (ad hoc on-demand distance vector). In NDM the information of every hop is recorded during the route discovery phase, which can not only discover the node disjoint path, but also solve the problem of loop-free path simply. We also study the number of multipath in theory, The simulation show that when nodes move at higher speed the performance of NDM is obvious better than AODV in aspects such as packet delivery fraction, average end-to-end delay and route discovery frequency. Aiming at the problem that there would be network traffic congestion when the network load is heavy, Traffic Balanced NDM(TB_NDM) is proposed . In this protocol, each node, based on its localMAC load status, decides whether it can accept routing requests from other nodes or not, the node with heavy traffic load will not become intermediate node in new route, Simulation results show that TB_NDM achieves better overall perfonnance over NDM.An ad hoc network is a dynamically reconfigurable wireless network with no fixed infrastructure, so the network security research will be confronted with many new issues. Authentication service is the implementation basis of mobile ad hoc network with security; Data communications can be implemented between mobile users securely by the use of certificate service. A traditional centralized or hierarchical certification authority solution does not fit in with ad hoc network because the lack of centralized control. The paper has made a preliminary study on certificate signature of mobile ad hoc network, The certification service must adopt distribute architecture in Mobile Ad Hoc Networks environment due to the absence of infrastructure and center. Existing distribute authentication technology is a kind of one hop architecture based on (n,t) threshold secret sharing cryptography, in which a node can not work properly when the amount of its one hop neighbor is less than threshold value. This paper introduces DCS-BA(distributed certification signature based on agent), which can solve the problem of lack of neighbor node in the one hop distributed certification signature algorithm, on the other hand can verify the validity of private key share due to adopting Feldman verification scheme. Aiming at the main exiting problems of distributed certification signature, a certificate...