The Impact Of Hybrid Quarantine Strategies And Delay Factor On Viral Prevalence In Computer Networks

With the fast development of Internet and the growth of network complexity, the issue of network security is becoming increasingly significant. Among which, one of the most powerful weapons for security threaten is the computer virus because of its fast propagation,large pervasive scale and severe destructive impact. A deep understanding for the computer virus propagation mechanism is necessary for defending and controlling the massive outbreak of computer virus, and has very important practical significance for information security management.In this paper, by analyzing the features of typical viruses and considering the impact of security software products on computer virus transmission, rational virus propagation models are proposed. Then the dynamic behaviors of the models are investigated. The main contributions made in this thesis are listed below.(1) Consider the fact that the hybrid quarantine strategies based on the hybrid intrusion detection system can affect the spread of computer virus. In this thesis, a new virus propagation model with the same quarantine rate, which is known as the SLBQRS model, is proposed. A deep study of this model is carried out and the stability of equilibrium of this model is obtained. Some numerical simulations are provided to support our theoretical results which also imply that hybrid quarantine strategies can inhibit viral spread effectively.(2) Latent is a common feature of computer virus, that is to say there is a latent period before a latent computer breaks out. So the delay factor should be considered in a real computer virus propagation model. Consider the fact that the susceptible computer, latentcomputer and breaking-out computer can be quarantined with different quarantine rates, in this thesis, a new computer virus propagation model with different quarantine rates named delayed SLBQRS model is established. By regarding the delay as bifurcating parameter and analyzing the associated characteristic equation, the dynamical behaviors, including local asymptotical stability in which the virus spreading can be controlled, and furthermore, local Hopf bifurcation occurs in the system, which implies computer virus is out of control, are investigated. By applying the normal form and center manifold theorem, the direction of Hopf bifurcation and the stability of bifurcating periodic solutions are also determined. Some numerical simulations are provided to support our theoretical results.