Worm Propagation Model Considering Node Heterogeneity

Worm is a common computer virus that is extremely aggressive and harmful.In computer networks,worm can cause large-scale network defects in a very short period of time due to the characteristics of self-replication and active propagation.In order to minimize the impact of worm outbreaks on the network,it is necessary to model the worm propagation process,reveal its propagation rules in the network,and provide a powerful theoretical basis for formulating feasible and effective defense strategies.In this paper,worm propagation process is deeply studied,and the heterogeneity of nodes in the network is discussed from the two aspects of infection probability and propagation probability.The main research work and contributions are as follows:(1)The worm propagation process was analyzed in detail,and the two processes of attack initiation and intrusion penetration in the attack penetration phase were respectively defined as the propagation process and infection process of the worm attack,thereby establishing the worm propagation model STIR.(2)Based on the worm propagation model STIR,a worm propagation model considering attack correlation is established.Firstly,the definition of attack correlation is given.Then,the dynamic change characteristics of node infection probability under attack correlation conditions are discussed and quantitatively characterized.Then,the state transition probability method is used to construct the worm propagation dynamics equation,and the calculation formula of propagation threshold is derived.Finally,the simulation analysis is carried out in the scale-free network.The experimental results verify the correctness of propagation threshold.Compared with the worm propagation model without considering attack correlation,this model can simulate the worm propagation process better.At the same time,it was also discovered in the study that the increase in the initial value of the infection probability,the rate of infection change and the propagation probability will also accelerate the speed and scale of worm propagation.(3)Based on the worm propagation model STIR,a worm propagation model STIDR based on trust model is established.Firstly,the trust model is described,then the influence of trust degree index on the worm propagation process is discussed,and the relationship between trust degree and propagation probability is quantitatively described.Aiming at the shortcomings of the existing trust model,the response strategy of trust degree to the risk of worm attack is introduced.The trust degree is updated in the three cases of direct risk,indirect risk and attack propagation risk.Finally,relying on the scale-free network,the effect of trust on the worm propagation process and the validity of the trust update calculation considering the risk of worm propagation are studied.The simulation results show that the trust model proposed in this paper can help identify malicious nodes and reduce the scale of worm propagation in the network.In summary,this paper mainly analyzes the worm propagation process based on node heterogeneity.The results of the above work enrich the research in the field of virus transmission,provide a new idea for modeling the later worm propagation,and provide a new mechanism reference against worm attacks.