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Giuseppe Della Penna, Benedetto Intrigila, Igor Melatti, Enrico Tronci, and Marisa Venturini Zilli. "Finite horizon analysis of Markov Chains with the Mur$\varphi$ verifier." Int. J. Softw. Tools Technol. Transf. 8, no. 4 (2006): 397–409. Springer-Verlag. ISSN: 1433-2779. DOI: 10.1007/s10009-005-0216-7.
Abstract: In this paper we present an explicit disk-based verification algorithm for Probabilistic Systems defining discrete time/finite state Markov Chains. Given a Markov Chain and an integer k (horizon), our algorithm checks whether the probability of reaching an error state in at most k steps is below a given threshold. We present an implementation of our algorithm within a suitable extension of the Mur$\varphi$ verifier. We call the resulting probabilistic model checker FHP-Mur$\varphi$ (Finite Horizon Probabilistic Mur$\varphi$). We present experimental results comparing FHP-Mur$\varphi$ with (a finite horizon subset of) PRISM, a state-of-the-art symbolic model checker for Markov Chains. Our experimental results show that FHP-Mur$\varphi$ can handle systems that are out of reach for PRISM, namely those involving arithmetic operations on the state variables (e.g. hybrid systems).
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Giuseppe Della Penna, Daniele Magazzeni, Alberto Tofani, Benedetto Intrigila, Igor Melatti, and Enrico Tronci. "Automated Generation of Optimal Controllers through Model Checking Techniques." In Icinco-Icso, edited by J. Andrade-Cetto, J. - L. Ferrier, J. M. C. D. Pereira and J. Filipe, 26–33. INSTICC Press, 2006. ISSN: 972-8865-59-7. DOI: 10.1007/978-3-540-79142-3.
Abstract: We present a methodology for the synthesis of controllers, which exploits (explicit) model checking techniques. That is, we can cope with the systematic exploration of a very large state space. This methodology can be applied to systems where other approaches fail. In particular, we can consider systems with an highly non-linear dynamics and lacking a uniform mathematical description (model). We can also consider situations where the required control action cannot be specified as a local action, and rather a kind of planning is required. Our methodology individuates first a raw optimal controller, then extends it to obtain a more robust one. A case study is presented which considers the well known truck-trailer obstacle avoidance parking problem, in a parking lot with obstacles on it. The complex non-linear dynamics of the truck-trailer system, within the presence of obstacles, makes the parking problem extremely hard. We show how, by our methodology, we can obtain optimal controllers with different degrees of robustness.
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Andrea Bobbio, Ester Ciancamerla, Michele Minichino, and Enrico Tronci. "Functional analysis of a telecontrol system and stochastic measures of its GSM/GPRS connections." Archives of Transport – International Journal of Transport Problems 17, no. 3-4 (2005).
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Edoardo Campagnano, Ester Ciancamerla, Michele Minichino, and Enrico Tronci. "Automatic Analysis of a Safety Critical Tele Control System." In 24th International Conference on: Computer Safety, Reliability, and Security (SAFECOMP), edited by R. Winther, B. A. Gran and G. Dahll, 94–107. Lecture Notes in Computer Science 3688. Fredrikstad, Norway: Springer, 2005. ISSN: 3-540-29200-4. DOI: 10.1007/11563228_8.
Abstract: We show how the Mur$\varphi$ model checker can be used to automatically carry out safety analysis of a quite complex hybrid system tele-controlling vehicles traffic inside a safety critical transport infrastructure such as a long bridge or a tunnel. We present the Mur$\varphi$ model we developed towards this end as well as the experimental results we obtained by running the Mur$\varphi$ verifier on our model. Our experimental results show that the approach presented here can be used to verify safety of critical dimensioning parameters (e.g. bandwidth) of the telecommunication network embedded in a safety critical system.
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Benedetto Intrigila, Daniele Magazzeni, Igor Melatti, and Enrico Tronci. "A Model Checking Technique for the Verification of Fuzzy Control Systems." In CIMCA '05: Proceedings of the International Conference on Computational Intelligence for Modelling, Control and Automation and International Conference on Intelligent Agents, Web Technologies and Internet Commerce Vol-1 (CIMCA-IAWTIC'06), 536–542. Washington, DC, USA: IEEE Computer Society, 2005. ISSN: 0-7695-2504-0-01. DOI: 10.1109/CIMCA.2005.1631319.
Abstract: Fuzzy control is well known as a powerful technique for designing and realizing control systems. However, statistical evidence for their correct behavior may be not enough, even when it is based on a large number of samplings. In order to provide a more systematic verification process, the cell-to-cell mapping technology has been used in a number of cases as a verification tool for fuzzy control systems and, more recently, to assess their optimality and robustness. However, cell-to-cell mapping is typically limited in the number of cells it can explore. To overcome this limitation, in this paper we show how model checking techniques may be instead used to verify the correct behavior of a fuzzy control system. To this end, we use a modified version of theMurphi verifier, which ease the modeling phase by allowing to use finite precision real numbers and external C functions. In this way, also already designed simulators may be used for the verification phase. With respect to the cell mapping technique, our approach appears to be complementary; indeed, it explores a much larger number of states, at the cost of being less informative on the global dynamic of the system.
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Giuseppe Della Penna, Benedetto Intrigila, Igor Melatti, and Enrico Tronci. "Exploiting Hub States in Automatic Verification." In Automated Technology for Verification and Analysis: Third International Symposium, ATVA 2005, Taipei, Taiwan, October 4-7, 2005, Proceedings, edited by D.A. Peled and Y.-K. Tsay, 54–68. Lecture Notes in Computer Science 3707. Springer, 2005. ISSN: 3-540-29209-8. DOI: 10.1007/11562948_7.
Abstract: In this paper we present a new algorithm to counteract state explosion when using Explicit State Space Exploration to verify protocol-like systems. We sketch the implementation of our algorithm within the Caching Mur$\varphi$ verifier and give experimental results showing its effectiveness. We show experimentally that, when memory is a scarce resource, our algorithm improves on the time performances of Caching Mur$\varphi$ verification algorithm, saving between 16% and 68% (45% on average) in computation time.
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Roberto Gorrieri, Ruggero Lanotte, Andrea Maggiolo-Schettini, Fabio Martinelli, Simone Tini, and Enrico Tronci. "Automated analysis of timed security: a case study on web privacy." International Journal of Information Security 2, no. 3-4 (2004): 168–186. DOI: 10.1007/s10207-004-0037-9.
Abstract: This paper presents a case study on an automated analysis of real-time security models. The case study on a web system (originally proposed by Felten and Schneider) is presented that shows a timing attack on the privacy of browser users. Three different approaches are followed: LH-Timed Automata (analyzed using the model checker HyTech), finite-state automata (analyzed using the model checker NuSMV), and process algebras (analyzed using the model checker CWB-NC). A comparative analysis of these three approaches is given.
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Ruggero Lanotte, Andrea Maggiolo-Schettini, Simone Tini, Angelo Troina, and Enrico Tronci. "Automatic Covert Channel Analysis of a Multilevel Secure Component." In Information and Communications Security, 6th International Conference, ICICS 2004, Malaga, Spain, October 27-29, 2004, Proceedings, edited by J. Lopez, S. Qing and E. Okamoto, 249–261. Lecture Notes in Computer Science 3269. Springer, 2004. DOI: 10.1007/b101042.
Abstract: The NRL Pump protocol defines a multilevel secure component whose goal is to minimize leaks of information from high level systems to lower level systems, without degrading average time performances. We define a probabilistic model for the NRL Pump and show how a probabilistic model checker (FHP-mur$\varphi$) can be used to estimate the capacity of a probabilistic covert channel in the NRL Pump. We are able to compute the probability of a security violation as a function of time for various configurations of the system parameters (e.g. buffer sizes, moving average size, etc). Because of the model complexity, our results cannot be obtained using an analytical approach and, because of the low probabilities involved, it can be hard to obtain them using a simulator.
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Marco Martinelli, Enrico Tronci, Giovanni Dipoppa, and Claudio Balducelli. "Electric Power System Anomaly Detection Using Neural Networks." In 8th International Conference on: Knowledge-Based Intelligent Information and Engineering Systems (KES), edited by M. G. Negoita, R. J. Howlett and L. C. Jain, 1242–1248. Lecture Notes in Computer Science 3213. Wellington, New Zealand: Springer, 2004. ISSN: 3-540-23318-0. DOI: 10.1007/978-3-540-30132-5_168.
Abstract: The aim of this work is to propose an approach to monitor and protect Electric Power System by learning normal system behaviour at substations level, and raising an alarm signal when an abnormal status is detected; the problem is addressed by the use of autoassociative neural networks, reading substation measures. Experimental results show that, through the proposed approach, neural networks can be used to learn parameters underlaying system behaviour, and their output processed to detecting anomalies due to hijacking of measures, changes in the power network topology (i.e. transmission lines breaking) and unexpected power demand trend.
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Ruggero Lanotte, Andrea Maggiolo-Schettini, Simone Tini, Angelo Troina, and Enrico Tronci. "Automatic Analysis of the NRL Pump." Electr. Notes Theor. Comput. Sci. 99 (2004): 245–266. DOI: 10.1016/j.entcs.2004.02.011.
Abstract: We define a probabilistic model for the NRL Pump and using FHP-mur$\varphi$ show experimentally that there exists a probabilistic covert channel whose capacity depends on various NRL Pump parameters (e.g. buffer size, number of samples in the moving average, etc).
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