论文标题
使用非确定性主管执行监督控制的不透明度
Opacity Enforcing Supervisory Control using Non-deterministic Supervisors
论文作者
论文摘要
在本文中，我们在离散事件系统的背景下通过监督控制调查了不透明度的执行。如果以被动观察者为模型的入侵者永远无法自信地推断系统处于秘密状态，则据说系统被认为是不透明的。设计目标是综合主管，以使闭环体系即使是公开知道的，即使控制政策是不透明的。在本文中，我们提出了一种使用非确定性主管来执行不透明度的新方法。非确定性主管是一种决策机制，在每次瞬间提供一组控制决策，并随机从决策集中选择一个特定的控制决策来实际控制工厂。与标准确定性控制机制相比，这种非确定性控制机制可以增强受控系统的合理可否认性，因为在线控制决策是随机实现的，不能从控制策略中暗示地推断出来。我们为合成非确定性的不透明度增强主管提供了一种声音和完整的算法。此外，我们表明，在某种意义上，即使确定性的主管无法执行不透明度，非确定性的主管比确定性的主管更强大地比确定性主管更强大。
In this paper, we investigate the enforcement of opacity via supervisory control in the context of discrete-event systems. A system is said to be opaque if the intruder, which is modeled as a passive observer, can never infer confidently that the system is at a secret state. The design objective is to synthesize a supervisor such that the closed-loop system is opaque even when the control policy is publicly known. In this paper, we propose a new approach for enforcing opacity using non-deterministic supervisors. A non-deterministic supervisor is a decision mechanism that provides a set of control decisions at each instant, and randomly picks a specific control decision from the decision set to actually control the plant. Compared with the standard deterministic control mechanism, such a non-deterministic control mechanism can enhance the plausible deniability of the controlled system as the online control decision is a random realization and cannot be implicitly inferred from the control policy. We provide a sound and complete algorithm for synthesizing a non-deterministic opacity-enforcing supervisor. Furthermore, we show that non-deterministic supervisors are strictly more powerful than deterministic supervisors in the sense that there may exist a non-deterministic opacity-enforcing supervisor even when deterministic supervisors cannot enforce opacity.
