Abstract: Based on both-branch fuzzy logic and Fuzzy Petri Net（FPN），a new network attack model named Both-Branch Fuzzy Logic Petri-net Attack Net（BBFLPAN） is put forward.The promoting and suppressive factors to network attack are analyzed in this attack model.In order to make fine distinction between attack actions and effects，the process of attack and defense actions are depicted as the place of FPN and the system states are depicted as the transition.The changes of network attack states can be represented directly.Based on the both-branch fuzzy logic analysis，a reasoning algorithm is proposed which applies incertitude consequence way and the effectiveness of the algorithm is verified by experiment.This paper originally considers together the factors pro-and-con that has effect on attack so that a closer network attack description to reality is made by this model.

Key words: fuzzy Petri net, both-branch fuzzy logic, attack modeling

摘要： 以双枝模糊逻辑和模糊Petri网（Fuzzy Petri net，FPN）理论为基础，定义了一种全新的网络攻击模型BBFLPAN，将网络攻击中对攻击起促进与抑制作用的两方面进行综合考虑与分析，用变迁表示攻击、防御行为的产生发展过程，库所表示系统所处的状态，将网络攻击与防御行为和攻击与防御结果进行了区分，直观地表示网络攻击的演变情况。同时结合双枝模糊逻辑，分析了BBFLPAN模型的基本推理规则，并提出了BBFLPAN的推理算法，并通过实验验证了算法的正确性。将对网络攻击实施起正反两方面的因素一起考虑和分析，使其对网络攻击的描述更加切近实际情况。

关键词: 模糊Petri网, 双枝模糊逻辑, 攻击建模