Theoretical Research On Trust Management Of WSNs Based On Evolutionary Game Theory

With the continuous development and progress of science and technology,WSNs(Wireless Sensor Networks)have been a large-scale application in our life,among which safety problems are gradually exposed along with the extension of the application.Besides the traditional safety problems,researchers focus on WSNs trust management issues.Owing to the characteristics of the volume and structure of micro sensor nodes,they lead to the energy be limited.In the process of communication,they refuse to forward packets for other nodes frequently on selfishness.And some normal nodes could be transformed malicious nodes by attackers,and then forward packets maliciously,affect the normal use of the network and shorten the network service life.Trust management makes normal communication among normal nodes,refuses the request of forwarding packets between free rides and malicious nodes and make the normal use of the whole network by building trust model among nodes.For every nodes,adopting trust cooperation politics can increase trust value and gain trust income,yet pay the corresponding price,for example,being used by malicious nodes,personal energy consumption etc.Due to refusing to forward packets for other nodes on selfishness,it is adopting distrust politics and refusing cooperation,that may decrease trust value and lead to reduce income.Aimed at the contradictory state,this paper builds trust management model based on evolutionary game theory,which guides the majority of nodes in the network to choose the trust cooperation strategy,makes the entire network can eventually provide services.Concretely,the research jobs of this paper are as follows:1.This paper carries out evolutionary simulation for wireless sensor network,when normal nodes in the network do not use the defense strategy,the network will be quickly paralyzed and be unable to provide normal services,due to be attacked by malicious nodes.In order to avoid this situation,the paper introduces the defense strategy mechanism.Under this mechanism,normal nodes can choose defense strategy to avoid malicious consumption when attacked against malicious nodes,it can make the entire network not paralyzed,even when the network is attacked,it also can provide the service.2.Based on the consideration of the selfish nodes and becoming selfish nodes,nodes refuses to forward packets to other normal nodes,this paper introduces the difference incentive mechanism.The mechanism can make both nodes choose trust cooperation strategy more quickly relative to the traditional incentive mechanism.Under the action of the mechanism,it can effectively reduce the initial choice of trust strategy normal nodes ratio.The introduction of this mechanism makes the whole network quickly stabilized.3.According to many uncertain factors of the reality in the network,this paper adds the network unreliability in the process of trust evaluation.According to simulation analysis of the packet loss rate and return delay,this paper finds the higher the loss rate is,the more unfavorable the stability of network is.Reducing the packet loss rate and return delay can also reduces the initial choice of trust strategy normal nodes ratio.It has a certain guiding significance for the actual network situation.This paper studies the trust management model of WSNs nodes based on evolutionary game theory,reveals the rule of trust evolution of WSNs and provides a theoretical basis for the follow-up of the actual network.