基于威胁传播采样的复杂信息系统风险评估

互联网时代的信息安全已成为全社会关注的问题之一.信息系统是信息的载体，为有效评估大规模分布式复杂信息系统的风险，构建了一种基于威胁传播采样的复杂信息系统风险评估方法.该方法考虑到威胁在复杂信息系统中传播时，对资产结点的转移状态以及资产结点发出的威胁传播边进行采样来生成威胁传播树(threat propagation trees, TPT)，然后通过计算威胁传播树中各资产结点的期望损失以及威胁传播树的概率来对整个复杂信息系统进行风险评估.实验分析表明，基于威胁传播采样的复杂信息系统风险评估方法，在生成威胁传播树时具有高效的时间效率，能够对复杂信息系统进行客观准确的风险评估，且在对复杂信息系统资产结点制定安全防护策略时，能够为安全风险管理者提供较为合理的安全指导建议.

Risk Evaluation of Complex Information System Based on Threat Propagation Sampling

Information security has been one of the focuses of social concern in the age of Internet. There is no doubt that accurately assessing the security of information medium is becoming the focus of the present information security work. For evaluating the risk of the large-scale distributed complex information system, we propose a risk evaluation method of the complex information system based on threat propagation sampling. Firstly, when the threats propagate in the complex information system, the number of threat propagation trees (TPT) is reduced by sampling the transition states of the asset nodes and the threat propagation edges emitted by the asset nodes, then computing the expected value loss of each node in the threat propagation tree and the probability of each threat propagation tree to evaluate the risk of the complex information system. The experimental analysis not only shows the risk evaluation proposed in this paper has higher time-efficient compared with the traditional combined strategy when producing the threat propagation tree, but also can make an objective and accurate risk evaluation. Furthermore, it can give more comprehensive and rational security-guide advices for security-risk managers when developing some security protection strategies on the asset nodes of the complex information system.