Research On Two Types Of Delayed Network Virus Propagation Models With Immune Strategies

With the continuous development of computer technology,not only people's way of life and work has undergone tremendous changes,but also the network informatization has reached an unprecedented height and breadth.The problem of network security and information security has become one of the most important problems in the process of human social development,which has aroused the high attention of the country and widespread concern of the people.General Secretary Xi Jinping once stressed at the meeting that "no network security has no national security",and the problem of network security has risen to the height of national strategy.Network virus is one of the biggest threats to network information security.In the face of the threat of network virus,people have taken a series of countermeasures,the main one is the countermeasures against the virus program code,but for many unknown network viruses,the existing anti-virus software can not completely remove them.Therefore,the macro level analysis of the transmission process of network virus can help to better analyze the process of virus transmission and understand the law of virus transmission,so as to better curb the spread of network virus and reduce the harm of network virus.Based on this idea and two kinds of network virus propagation models,this paper studies two kinds of delay network virus propagation models with immune strategy and nonlinear infection rate,considering the nonlinear infection rate,propagation delay and immune measures in the process of virus propagation.The main contents of this paper are as follows:1.Considering that the infection rate of network virus is not completely linear,a class of SVIR models with immune strategy and nonlinear infection rate are studied based on SVIR(Susceptible-Vaccinated-Infected-Recovered)network virus transmission model.The model assumes that some computers connected to the network are secure and some may carry viruses.When the immune strategy acts on the susceptible nodes,it has a certain probability to make them obtain the immune ability,but the nodes in the immune state also have the possibility to infect the network virus due to the incomplete effectiveness of the anti-virus software.Firstly,the stability of SVIR model with nonlinear delay and the properties of Hopf bifurcation when the instability is lost are studied by the central manifold theorem and the canonical type theory.Then,the dynamic change of the number of infected nodes in SVIR model with bilinear infection rate and nonlinear infection rate,the stability of the model and the effect of immune strategy efficiency on the virus transmission process were simulated by Matlab2017 a software.2.Furthermore,considering that network virus has not only time-delay in one link,a kind of double delays SEIVS(Susceptible-Exposed-Infected-Vaccinated-Susceptible)network virus transmission model with immune strategy and nonlinear infection rate is studied.The model assumes that the infection rate of network virus is nonlinear,and the efficiency of immune strategy is different for different computers in the network.Based on the SEIVS model,considering the latency delay in the process of virus infection and the temporary immune period delay in the process of computer node losing immunity after virus cleaning,a nonlinear double delays SEIVS network virus model with immune strategy is studied.The stability of the model under different combinations of two kinds of time delays is discussed,and the properties of Hopf bifurcation when the model loses stability are analyzed.Finally,the stability of the model and the influence of two kinds of time delay on virus propagation are simulated by Matlab2017 a.Based on two kinds of time-delay network virus propagation models with immune strategy and nonlinear infection rate,this paper analyzes the propagation law of computer virus from three aspects of virus infection rate,time-delay and immune strategy,and uses Matlab2017 a software to carry out computer simulation analysis on the theoretical results.The conclusion has certain reference significance for the prevention and control of network virus propagation.