利用攻防树实现网络安全风险分析及成本/效益控制

攻击树建模是一种传统的网络安全风险分析方法。在此基础上，提出了防御树建模方法，它能从防御的角度对安全防御措施、成本和可靠度等诸多因素进行逻辑分析，弥补了单从攻击角度评估网络安全风险的不足。在防御树建模的基础上，提出了优化安全防御措施的两种成本／效益控制算法，对算法的复杂度进行了分析。这两种算法能分别从成本优先和防御可靠度优先这两个角度对防御村进行裁剪。

USING ATTACK & DEFENCE TREE TO ANALYZE NETWORK SECURITY RISK AND TO PERFORM CONTROL OF COST-EFFICIENCY

Attack tree modeling is a traditional ,nethod to analyze network security risk. Based on this method, defence tree modeling is proposed. It can logically parse out many factors, such as security protection measures, costs, degree of defence reliability from the view of protection, which makes up the deficiency of evaluation on network security risk only from the point of attack. On the ground of defence tree modeling, two cost -efficiency optimizing control algorithms are introduced, their complexity is analyzed. These two algorithms can help to trim defence tree according to the cost first or the degree of defence reliability first respectively.