基于攻击图的信息物理融合系统渗透测试方法

信息物理融合系统(Cyber-Physical System,CPS)多为安全攸关系统,是网络攻击的高价值目标,需要对其进行有效的安全评估。为此,提出一种基于攻击图的信息物理融合系统渗透测试方法。首先,对传统攻击图进行改进,考虑物理攻击、攻击持续时间以及物理系统的连续变量值,提出适用于CPS的攻击图建模技术AGC(Attack Graph for CPS),并在图中增加攻击可行性参数以表示单步攻击的成功率；其次,基于AGC提出最优攻击路径选择策略,包括最小攻击代价、最短攻击时间等,并设计面向CPS的智能渗透测试算法；最后,通过应用实例对方法的有效性进行验证。分析结果表明,该方法能够根据渗透测试目标选择最优攻击路径,并能根据实际反馈结果自动调整后续攻击步骤,有效实现CPS的安全评估。

Penetration Testing Method for Cyber-Physical System Based on Attack Graph

As a typical example of security-related system,cyber-physical system (CPS) is the high-value target of network attack.Therefore,its security protection needs to be effectively assessed.To this end,a penetration testing method for CPS based on attack graph is proposed.Firstly,the traditional attack graph is improved and a new attack graph for CPS (AGC) is proposed.Specifically,the physical attack,the duration of the attack and the continuous variable value of physical system are considered in AGC.Additionally,the attack feasibility parameter is added to represent the success rate of single-step attack.Secondly,based on AGC,the optimal attack path selection strategies are represented,including the minimum attack cost,the shortest attack time and so on.Furthermore,the intelligent penetration testing algorithm is designed to accomplish automated penetration.Finally,the effectiveness of the proposed method is verified by case study.The results show that the method can select the optimal attack path to the target,intelligently adjust the subsequent attack steps according to the feedback,and assess the security of CPS effectively.