关键词: 网络攻击模型, 模糊时间Petri网, 双枝模糊决策, 可靠性

Abstract: Based on the fuzzy timed Petri net，which has time characteristics，a new network attack model is set up.In the model，mainly the both-branch fuzzy sets and reliability theory are introduced.This model uses the superior domain（or inferior domain） of the both-branch fuzzy sets to represent promoting factors（or hindering factors） of an attack respectively，carries on the both-branch fuzzy sets-based decisions to decide influencing effects on the places in a transition’s post-set after the transition（an attack behavior） is fired.In the model，an attacking process is abstracted as a complicated system that can be repaired.After random failure，attack states represented by places will enter into a repairable phase which has a fuzzy time interval，and resume to attacking states after the repairable phase.In this way，the model can conform more truly to the fact that an attacker always keeps an attack state to be favorable to his attack.Finally the attack route generating algorithm of the model and the reliability analysis of system are made，and a simulation example is made to show that the model has good performances.

Key words: network attack model, fuzzy timed Petri net, both-branch fuzzy sets-based decision, reliability