Availability Evaluation Of Heterogeneous Wsns Attacked By Malware

With the development of sensors and wireless communication technology,Wireless Sensor Networks(WSNs),especially Heterogeneous WSNs(HWSNs)have achieved applications in many areas,such as target tracking,military reconnaissance,health care and smart life.The advantages of HWSNs are strong pertinence,high flexibility,low cost,etc.However,due to the diversified environment of sensor nodes and their own energy limitations,they are vulnerable to malware attacks and node failure.In order to provide effective measures to enhance the security of HWSNs and inhibit the spread of malware,it is necessary to disclose the propagation of malware on HWSNs and to evaluate the availability of HWSNs.When a malicious program finds a security bug in the network system,it is easy to infect itself to the HWSNs node and further infect its neighbors,thus causing malware to spread to the entire network and leading the network to collapse.This dissertation focuses on the security issues of HWSNs attacked by malware.The main research contents and contributions are as follows:(1)In order to study the influence of node heterogeneity on the propagation behavior of malware in HWSNs,a node difference model was built,and propagation dynamics of malware propagation behaviors based on state transitions of HWSNs nodes were studied;(2)Based on the above research results,the formula for the steadystate availability of single nodes was obtained,and then the steady-state availability of star-shaped HWSNs and cluster-type HWSNs was analyzed.First of all,this dissertation constructs a heterogeneous model and a malware propagation model.Specifically,by observing the differences in node degree and node vulnerability in actual networks,a node difference model was constructed based on node vulnerability and node distribution;a malware propagation model was constructed using epidemic theory and Markov chain,and the status of HWSNs nodes was obtained.The experiment analyzed the distribution of node degree and the influence of node vulnerability function on the infection rate of nodes,and gave the analysis of the propagation process of malware under different vulnerability functions.The research results provided the theoretical basis for the research on the security issues of HWSNs that are attacked by malware.Secondly,this dissertation proposed an evaluation method for the availability of HWSNs attacked by malware.Specifically,based on the dynamic equation of state transition of HWSNs node,the formula for the probability of each state when the node reached a steady state was obtained,and then the formula for the availability of the node steady state was obtained;through the availability evaluation method,the star type was analyzed.The structural characteristics of HWSNs and cluster HWSNs were given,and the calculation methods for the steady availability of star HWSNs and cluster HWSNs were given.Simulation experiments analyzed the impact of different node vulnerability functions on the steady availability of individual nodes,star HWSNs,and cluster HWSNs,and analyzed the influence of the number of sensor nodes and the minimum number of available nodes on the steady availability of star HWSNs.The influence of the number of sensor nodes and the number of clusters on the steady availability of cluster HWSNs in a cluster.The results of the research had guiding significance for the effective deployment of HWSNs.