Reduced-Complexity Verification for K-Step and Infinite-Step Opacity in Discrete Event Systems (2310.11825v1)
Abstract: Opacity is a property that captures security concerns in cyber-physical systems and its verification plays a significant role. This paper investigates the verifications of K-step and infinite-step weak and strong opacity for partially observed nondeterministic finite state automata. K-step weak opacity is checked by constructing, for some states in the observer, appropriate state-trees, to propose a necessary and sufficient condition. Based on the relation between K-step weak and infinite-step weak opacity, a condition that determines when a system is not infinite-step weak opaque is presented. Regarding K-step and infinite-step strong opacity, we develop a secret-involved projected automaton, based on which we construct secret-unvisited state trees to derive a necessary and sufficient condition for K-step strong opacity. Furthermore, an algorithm is reported to compute a verifier that can be used to obtain a necessary and sufficient condition for infinite-step strong opacity. It is argued that, in some particular cases, the proposed methods achieve reduced complexity compared with the state of the art.
- S. Lafortune, F. Lin, and C. N. Hadjicostis, “On the history of diagnosability and opacity in discrete event systems,” Annual Reviews in Control, vol. 45, pp. 257–266, 2018.
- R. Jacob, J.-J. Lesage, and J.-M. Faure, “Overview of discrete event systems opacity: Models, validation, and quantification,” Annual reviews in control, vol. 41, pp. 135–146, 2016.
- Y. Guo, X. Jiang, C. Guo, S. Wang, and O. Karoui, “Overview of opacity in discrete event systems,” IEEE Access, vol. 8, pp. 48 731–48 741, 2020.
- X. Han, K. Zhang, J. Zhang, Z. Li, and Z. Chen, “Strong current-state and initial-state opacity of discrete-event systems,” Automatica, vol. 148, p. 110756, 2023.
- X. Yin, Z. Li, W. Wang, and S. Li, “Infinite-step opacity and K𝐾{K}italic_K-step opacity of stochastic discrete-event systems,” Automatica, vol. 99, pp. 266–274, 2019.
- F. Lin, “Opacity of discrete event systems and its applications,” Automatica, vol. 47, no. 3, pp. 496–503, 2011.
- A. Saboori and C. N. Hadjicostis, “Verification of K𝐾{K}italic_K-step opacity and analysis of its complexity,” IEEE Transactions on Automation Science and Engineering, vol. 8, no. 3, pp. 549–559, 2011.
- A. Saboori and C. N. Hadjicostis, “Verification of infinite-step opacity and complexity considerations,” IEEE Transactions on Automatic Control, vol. 57, no. 5, pp. 1265–1269, 2012.
- A. Saboori and C. N. Hadjicostis, “Verification of initial-state opacity in security applications of discrete event systems,” Information Sciences, vol. 246, pp. 115–132, 2013.
- Y. Falcone and H. Marchand, “Enforcement and validation (at runtime) of various notions of opacity,” Discrete Event Dynamic Systems, vol. 25, no. 4, pp. 531–570, 2015.
- X. Yin and S. Lafortune, “A new approach for the verification of infinite-step and K𝐾{K}italic_K-step opacity using two-way observers,” Automatica, vol. 80, pp. 162–171, 2017.
- J. Balun and T. Masopust, “Comparing the notions of opacity for discrete-event systems,” Discrete Event Dynamic Systems, vol. 31, no. 4, pp. 553–582, 2021.
- Z. Ma, X. Yin, and Z. Li, “Verification and enforcement of strong infinite- and K𝐾{K}italic_K-step opacity using state recognizers,” Automatica, vol. 133, p. 109838, 2021.
- Y. Tong, H. Lan, and C. Seatzu, “Verification of K𝐾{K}italic_K-step and infinite-step opacity of bounded labeled Petri nets,” Automatica, vol. 140, p. 110221, 2022.
- A. Wintenberg, M. Blischke, S. Lafortune, and N. Ozay, “A general language-based framework for specifying and verifying notions of opacity,” Discrete Event Dynamic Systems, vol. 32, pp. 253–289, 2022.
- X. Yin and S. Li, “Synthesis of dynamic masks for infinite-step opacity,” IEEE Transactions on Automatic Control, vol. 65, no. 4, pp. 1429–1441, 2020.
- Y.-C. Wu and S. Lafortune, “Synthesis of insertion functions for enforcement of opacity security properties,” Automatica, vol. 50, no. 5, pp. 1336–1348, 2014.
- R. Liu and J. Lu, “Enforcement for infinite-step opacity and K𝐾{K}italic_K-step opacity via insertion mechanism,” Automatica, vol. 140, p. 110212, 2022.
- C. Keroglou and S. Lafortune, “Embedded insertion functions for opacity enforcement,” IEEE Transactions on Automatic Control, vol. 66, no. 9, pp. 4184–4191, 2021.
- X. Li, C. N. Hadjicostis, and Z. Li, “Extended insertion functions for opacity enforcement in discrete event systems,” IEEE Transactions on Automatic Control, vol. 67, no. 10, pp. 5289–5303, 2022.
- Y. Ji and S. Lafortune, “Enforcing opacity by publicly known edit functions,” in 56th IEEE Conference on Decision and Control (CDC), 2017.
- X. Li, C. N. Hadjicostis, and Z. Li, “Opacity enforcement in discrete event systems using extended insertion functions under inserted language constraints,” IEEE Transactions on Automatic Control, vol. 68, no. 11, pp. 1–8, 2023.