Research Of Security Multicast Routing Protocol In Wireless Ad Hoc Networks

Ad-Hoc network is a decentralized,self-organized,resource constrained collaborative network,which has many applications such as multimedia conference,emergency rescue and disaster relief,video on demand,etc.,and needs one to many multicast communication.Multicast routing can extend the application range of wireless ad hoc networks.However,the network is vulnerable to internal attacks from malicious nodes,such as black hole attacks,which destroy the cooperation between nodes,resulting in the routing protocol can not operate normally.In order to solve the problem of routing security,trust model is often added to the routing protocol to identify malicious nodes through the calculation of trust degree.However,the operation of trust model will lead to the problem of excessive overhead.In addition,the selection of parameters in trust model can directly affect the network performance,and improper selection of parameters will lead to the problem of unsatisfactory network performance.Aiming at the above problems,this paper designs a tree like secure multicast route,which can resist network internal attacks(black hole / gray hole attack,switch attack)under the condition of reducing protocol overhead as much as possible.The main research work of this paper is divided into the following three points:First,the trust model is combined with tree multicast routing by improving the design of routing message to reduce the running cost of the protocol.Through the improved design of Hello message structure and its interaction mode,the recently updated trust degree is embedded in Hello message,so that one Hello message interaction can complete neighbor maintenance and trust degree interaction at the same time,reduce the additional sales brought by trust degree interaction in the trust model.In the case of no malicious nodes in the network,the protocol performance of the combination of trust model and multicast routing is analyzed.The results show that under the appropriate model parameters,the performance of routing overhead and delay is similar to that of MAODV,and the protocol running overhead is low.Secondly,in view of the problems of the classical trust model,such as the poor detection and defense ability of switch attacks and the selection of protocol parameters,the trust model is improved to recognize switch attacks in time by forgetting outdated information through time decay factor.Combined with NS-2 software,network internal attacks(black hole attack,switch attack)are simulated,and the results show that the model can resist the above attacks.In addition,the paper analyzes the selection of protocol parameters such as time decay factor and trust threshold in different network scenarios.Thirdly,in order to verify the availability and effectiveness of the designed secure multicast routing protocol,based on the laboratory ad hoc network equipment,the software design and implementation of secure multicast are carried out,and the corresponding network test scenarios are built for verification.The test results show that the designed secure multicast routing protocol can identify and deal with malicious nodes in the network.