Worm Propagation Model Under Multi System Coexistence

Today,the rapid development of the Internet,especially mobile Internet has become an essential part of people's lives.In people's daily life,communication,consulting,taxi,catering,finance and other aspects can be carried out on the mobile internet.This puts a higher demand for Internet security.However,computer worm has been a major threat to internet security.It has a very high speed of transmission and replication capabilities,it also can infect and destroy thousands of computers around the world,hamper people's normal life,and cause huge economic losses.In current operating system market,especially in smart phone operating system market,a variety of operating systems coexist.Some operating system fragmentize,and some old systems that can't get security support still have a considerable share of the market.This phenomenon has seriously hindered the protection of network security.It is very important to explore worm propagation by establishing the infectious disease model.However,there is not a model dividing the susceptible state(S state).This thesis divides S state into several states to simulate the real propagation of the worm,which represent several different operating systems.Based on the previous model,MultiS-IR model,MultiS-IQV model,MultiS-EIQV model and all-around MultiS-EIQV model are established.In addition,pulse vaccination and pulse quarantine will also be cited in these models.This thesis will also focus on the analysis of the stability of the above models,and find out the disease-free equilibrium of models.When the basic reproduction number is less than 1,models are stable at the disease-free equilibrium.At the end of each chapter,simulation experiments are used to simulate the propagation of each model,and further verify the stability of models.In addition,several important parameters in models are analyzed.