论文标题
网络物理系统对对手的隐私保护弹性
Privacy-Preserving Resilience of Cyber-Physical Systems to Adversaries
论文作者
论文摘要
预计网络物理系统(CPS)对多种对手有弹性。在本文中,我们考虑了必须在存在两种对手的情况下满足线性时间逻辑(LTL)目标的CP。第一个对手有能力篡改对CP的投入,以影响LTL目标的满意度。 CPS与此对手的相互作用被建模为随机游戏。我们合成CP的控制器,以最大程度地提高满足LTL目标的可能性。第二个对手是窃听者,他可以观察到从上一步产生的CP的标记轨迹。然后,它可以使用此信息来启动其他类型的攻击。标记的轨迹是一系列标签,其中标签与状态相关联,并且与该状态下LTL物镜的满意度相关。我们使用差异隐私来量化当窃听者看到标记的轨迹时相互关联的状态之间的不可区分性。如果两个相等长度的轨迹在各个轨迹沿每个状态差异私有,则它们在私有的情况下将是私有的。我们使用偏斜的Kantorovich指标来计算概率分布与根据相关状态策略所选择的行动所产生的状态的距离之间的距离,以量化差异隐私。此外,我们以不影响LTL目标满意度的方式来做到这一点。我们验证了必须在对抗环境中满足LTL目标的无人机模拟中的方法。
A cyber-physical system (CPS) is expected to be resilient to more than one type of adversary. In this paper, we consider a CPS that has to satisfy a linear temporal logic (LTL) objective in the presence of two kinds of adversaries. The first adversary has the ability to tamper with inputs to the CPS to influence satisfaction of the LTL objective. The interaction of the CPS with this adversary is modeled as a stochastic game. We synthesize a controller for the CPS to maximize the probability of satisfying the LTL objective under any policy of this adversary. The second adversary is an eavesdropper who can observe labeled trajectories of the CPS generated from the previous step. It could then use this information to launch other kinds of attacks. A labeled trajectory is a sequence of labels, where a label is associated to a state and is linked to the satisfaction of the LTL objective at that state. We use differential privacy to quantify the indistinguishability between states that are related to each other when the eavesdropper sees a labeled trajectory. Two trajectories of equal length will be differentially private if they are differentially private at each state along the respective trajectories. We use a skewed Kantorovich metric to compute distances between probability distributions over states resulting from actions chosen according to policies from related states in order to quantify differential privacy. Moreover, we do this in a manner that does not affect the satisfaction probability of the LTL objective. We validate our approach on a simulation of a UAV that has to satisfy an LTL objective in an adversarial environment.