Opacity Measures of Fuzzy Discrete Event Systems

Deng, Weilin; Qiu, Daowen; Yang, Jingkai

doi:10.1109/tfuzz.2020.3005335

Cited by 12 publications

(3 citation statements)

References 46 publications

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“…In 14 , Yang et al propose new types of opacity in networked DESs that are modeled as finite state automata (FSA) by taking into account the communication delays and losses in the observation channel. Opacity was also investigated in stochastic DESs modeled as probabilistic automata 15 and for fuzzy DESs modeled as fuzzy automata 16 , 17 , which extends the relevant findings of the opacity theory for classical DESs. It should be noted that when a system is evaluated to be non-opaque, opacity enforcement becomes crucial.…”

Section: Introductionsupporting

confidence: 58%

Current-state opacity verification in discrete event systems using an observer net

Labed

Saadaoui

et al. 2022

Sci Rep

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Due to the proliferation of contemporary computer-integrated systems and communication networks, there is more concern than ever regarding privacy, given the potential for sensitive data exploitation. A recent cyber-security research trend is to focus on security principles and develop the foundations for designing safety-critical systems. In this work, we investigated the problem of verifying current-state opacity in discrete event systems using labeled Petri nets. A system is current-state opaque provided that the current-state estimate cannot be revealed as a subset of secret states. We introduced a new sub-model of the system, named an observer net. The observer net have the same structure as the plant, but it is distinguished by the use of colored markers as well as simultaneous and recursive transition enabling and firing, which offer an efficient state estimation. We considered two settings of the proposed approach: an on-line setting, in which a current-state opacity algorithm is proposed. The algorithm waits for the occurrence of an observable event and determines if the current observation of a plant reveals the secret behaviour, as well as, an off-line setting, where the verification problem is solved based on a state estimator called a colored estimator. In this context, necessary and sufficient conditions for verifying opacity are developed with illustrative examples to demonstrate the presented approach.

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Section: Introductionsupporting

confidence: 58%

Current-state opacity verification in discrete event systems using an observer net

Labed

Saadaoui

et al. 2022

Sci Rep

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“…When an original system is not opaque, its opacity enforcement problem has been extensively studied using a variety of techniques (see, e.g., previous studies [16][17][18][19][20]). Furthermore, verification and enforcement of opacity have been extended to other classes of models, including Petri nets [21,22], stochastic DESs [23], modular DESs [24], fuzzy DESs [25], and others [26,27]. For details, we refer the reader to the comprehensive review [28] and the references therein.…”

Section: Introductionmentioning

confidence: 99%

Opacity of discrete‐event systems under nondeterministic observation mechanism

Zhang

Chu

Han

et al. 2022

Asian Journal of Control

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For some practical systems modeled by discrete‐event systems (DESs), the event observation mechanism may be no longer static/fixed due to sensor faults/failures, packet loss, and/or measurement uncertainties. It is required to redefine the observations of events. Therefore, it is interesting to reconsider the opacity in the context of abnormal conditions as mentioned. In this paper, we extend notions of initial‐state opacity (ISO), current‐state opacity (CSO), and initial‐and‐final‐state opacity (IFSO) in a standard setting to an advanced framework of nondeterministic observations (i.e., the event‐observation mechanism is state‐dependent and nondeterministic) by taking the output‐observation‐equivalence instead of the natural projection‐equivalence into account. To efficiently verify them, we construct three new matrix‐based information structures in this advanced framework called an initial‐state estimator, a current‐state estimator, and an initial‐and‐final‐state estimator using the Boolean semi‐tensor product (BSTP) theory. Accordingly, the matrix‐based criteria for verifying these three types of opacity are given, respectively. Computational complexity analysis as well as illustrative examples are also provided for the proposed results.

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“…networked systems [16], [17], Petri nets [18]- [20], cyberphysical systems [21], [22], probabilistic systems [23], [24] fuzzy systems [25], [26], and the other systems [27]- [29].…”

Section: Introductionmentioning

confidence: 99%

Opacity of Fuzzy Discrete Event Systems

Deng

Yang

Cheng

et al. 2019

2019 Chinese Control and Decision Conference (CCDC)

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Finite automata (FAs) model is a popular tool to characterize discrete event systems (DESs) due to its succinctness. However, for some complex systems, it is difficult to describe the necessary details by means of FAs model. In this paper, we consider a kind of extended finite automata (EFAs) in which each transition carries a predicate over state and event parameters. We also consider a type of simplified EFAs, called Event-Parameters EFAs (EP-EFAs), where the state parameters are removed. Based upon these two parametric models, we investigate the problem of opacity analysis for parametric DESs. First of all, it is shown that EFAs model is more expressive than EP-EFAs model. Secondly, it is proved that the opacity properties for EFAs are undecidable in general. Moreover, the decidable opacity properties for EP-EFAs are investigated. We present the verification algorithms for current-state opacity, initial-state opacity and infinite-step opacity, and then discuss the complexity. This paper establishes a preliminary theory for the opacity of parametric DESs, which lays a foundation for the opacity analysis of complex systems.

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Opacity Measures of Fuzzy Discrete Event Systems

Cited by 12 publications

References 46 publications

Current-state opacity verification in discrete event systems using an observer net

Current-state opacity verification in discrete event systems using an observer net

Opacity of discrete‐event systems under nondeterministic observation mechanism

Opacity of Fuzzy Discrete Event Systems

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