一种新的系统等级测评不确定性演化推理模型

A New Uncertainty Evolution Inference Model for Classified Evaluation of Information System

为了更加合理地判定系统综合保护能力是否达到相应的等级要求,将测评标准GB/T 22239—2008中的安全要素与信息安全事件进行关联分析,利用故障树对安全事件进行分解,并将故障树的最小割集转化成推理规则;利用不确定推理技术推导系统脆弱性可能引发的安全事件,计算损失大小和风险值,将它作为系统保护能力评价的参考依据.以某网站为例进行实验,结果表明该模型能够根据系统的脆弱性进行合理的风险计算,提高了等级测评结论的合理性,为等级保护与风险分析进行有机结合提供了可能.

To evaluate reasonably the ability of protection system,the requirements of evaluation standard GB/T 22239-2008 and information security events have to be considered and analyzed comprehensively.The fault tree is applied to decomposition of security incidents and the minimal cut set of fault tree can be translated into inference rules.Then,the uncertain reasoning technique is used to derive security incidents caused probably by system vulnerability.The loss and risk are taken into account,which could be regarded as the basis to assess the capacity of protection system.Experimental results show that the performance of proposed model is corresponding to the system vulnerability and the judgment of classified assessment is reasonable.Above work provides a possible route to synthesize the search of classified protection and risk analysis.