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Cyber Physical Systems Resiliency 2015 |
The research work cited here looks at the Science of Security hard problem of Resiliency in the context of cyber physical systems. The work was presented in 2015.
K. G. Lyn, L. W. Lerner, C. J. McCarty and C. D. Patterson, “The Trustworthy Autonomic Interface Guardian Architecture for Cyber-Physical Systems,” Computer and Information Technology; Ubiquitous Computing and Communications; Dependable, Autonomic and Secure Computing; Pervasive Intelligence and Computing (CIT/IUCC/DASC/PICOM), 2015 IEEE International Conference on, Liverpool, 2015, pp. 1803-1810. doi: 10.1109/CIT/IUCC/DASC/PICOM.2015.263
Abstract: The growing connectivity of cyber-physical systems (CPSes) has led to an increased concern over the ability of cyber-attacks to inflict physical damage. Current cyber-security measures focus on preventing attacks from penetrating control supervisory networks. These reactive techniques, however, are often plagued with vulnerabilities and zero-day exploits. Embedded processors in CPS field devices often possess little security of their own, and are easily exploited once the network is penetrated. We identify four possible outcomes of a cyber-attack on a CPS embedded processor. We then discuss five trust requirements that a device must satisfy to guarantee correct behavior through the device's lifecycle. Next, we examine the Trustworthy Autonomic Interface Guardian Architecture (TAIGA) which monitors communication between the embedded controller and physical process. This autonomic architecture provides the physical process with a last line of defense against cyber-attacks. TAIGA switches process control to a trusted backup controller if an attack causes a system specification violation. We conclude with experimental results of an implementation of TAIGA on a hazardous cargo-carrying robot.
Keywords: cyber-physical systems; trusted computing; CPS embedded processor; TAIGA; cyber-attacks; cyber-security measures; embedded controller; physical process; reactive techniques; trusted backup controller; trustworthy autonomic interface guardian architecture; Control systems; Process control; Program processors; Sensors; Trojan horses; Cyber-physical systems; autonomic control; embedded device security; resilience; trust (ID#: 16-11027)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7363316&isnumber=7362962
A. Astarloa, N. Moreira, U. Bidarte, M. Urbina and D. Modrono, “FPGA Based Nodes for Sub-Microsecond Synchronization of Cyber-Physical Production Systems on High Availability Ring Networks,” 2015 International Conference on ReConFigurable Computing and FPGAs (ReConFig), Mexico City, 2015, pp. 1-6. doi: 10.1109/ReConFig.2015.7393316
Abstract: Cyber-Physical Production Systems are characterized by integrating sensors, processing and communication in Industrial Environments like in advanced manufacturing plants or in the new generation Smart Grids. In these contexts, the accuracy on the synchronization plays a vital role because it is the base for control operations and for the correlation among the distributed sensor data sampling. In this paper the application of the IEEE1588 Synchronization protocol over High Availability Ethernet networks is applied to a new generation Cyber-Physical Production Systems in order to achieve sub-microsecond synchronization. These CPPS can be used to build rings and to interconnect rings as well. These interconnections offer bumpless Ethernet redundancy, without the need of any additional network equipment. In order to measure the resilience and the accuracy of the 1588-aware high-availability network composed by these nodes, a distributed sensors implementation composed by HSR network nodes that benefits from reconfigurable technology (small FPGAs and powerful programmable SoCs)has been analyzed. As it has been verified, although in a case of network failure, the synchronization recovers automatically and the accuracy obtained is in the range of 1 μs, that offers a very good reference for many applications in the industry.
Keywords: LAN interconnection; cyber-physical systems; distributed sensors; field programmable gate arrays; local area networks; sampling methods; synchronisation; system-on-chip; 1588-aware high-availability network; CPPS; Ethernet redundancy; FPGA based node; HSR network node; IEEE1588 synchronization protocol; advanced manufacturing plant; cyber-physical production system; distributed sensor data sampling; distributed sensors implementation; high availability ethernet network; industrial environment; integrating sensor; interconnection; network equipment; network failure; powerful programmable SoC; reconfigurable technology; ring network; smart grid; submicrosecond synchronization; IP networks; Logic gates; Peer-to-peer computing; Ports (Computers); Sensors; Switches; Synchronization; Cyber-Physical Systems; Cyber-physical Production Systems; FPGA; High-availability Seamless Redundancy (HSR); IEC 61850; IEC 62439; IEC 62439-3-5; IEEE 1588; Industrie 4.0; Precise Time Protocol; Programmable SoC; Sensors Networks; Zynq (ID#: 16-11028)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7393316&isnumber=7393279
S. Gujrati, H. Zhu and G. Singh, “Composable Algorithms for Interdependent Cyber Physical Systems,” Resilience Week (RWS), 2015, Philadelphia, PA, 2015, pp. 1-6. doi: 10.1109/RWEEK.2015.7287431
Abstract: Cyber-Physical Systems (CPS) applications are being increasingly used to provide services in domains such as health-care, transportation, and energy. Providing such services may require interactions between applications, some of which may be unpredictable. Understanding and mitigating such interactions require that CPSs be designed as open and composable systems. Composition has been studied extensively in the literature. To complement this work, this paper studies composition of cyber algorithms with user behaviors in a CPS. Traditional middleware algorithms have been designed by abstracting away the underlying system and providing users with high-level APIs to interact with the physical system. In a CPS, however, users may interact directly with the physical system and may perform actions that are part of the services provided. We find that by accounting for user interactions and including them as part of the solution, one can design algorithms that are more efficient, predictable and resilient. To accomplish this, we propose a framework to model both the physical and the cyber systems. This framework allows specification of both physical algorithms and cyber algorithms. We discuss how such specifications can be composed to design middleware that leverages user actions. We show that such composite solutions preserve invariants of the component algorithms such as those related to functional properties and fault-tolerance. Our future work involves developing a comprehensive framework that uses compositionality is a key feature to address interdependent behavior of CPSs.
Keywords: formal specification; human computer interaction; middleware; object-oriented programming; open systems; software fault tolerance; user centred design; CPS applications; CPS interdependent behavior; component algorithm; composable algorithms; composable systems; cyber algorithm; energy domain; fault-tolerance; functional properties; health-care domain; high-level API; interdependent cyber-physical systems; middleware algorithm design; middleware design; open systems; physical system interaction; specification composition; transportation domain; user action; user behavior; user interaction; Algorithm design and analysis; Computational modeling; Middleware; Prediction algorithms; Sensors; Vehicles (ID#: 16-11029)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7287431&isnumber=7287407
G. Martins, S. Bhatia, X. Koutsoukos, K. Stouffer, C. Tang and R. Candell, “Towards a Systematic Threat Modeling Approach for Cyber-Physical Systems,” Resilience Week (RWS), 2015, Philadelphia, PA, 2015, pp. 1-6. doi: 10.1109/RWEEK.2015.7287428
Abstract: Cyber-Physical Systems (CPS) are systems with seamless integration of physical, computational and networking components. These systems can potentially have an impact on the physical components, hence it is critical to safeguard them against a wide range of attacks. In this paper, it is argued that an effective approach to achieve this goal is to systematically identify the potential threats at the design phase of building such systems, commonly achieved via threat modeling. In this context, a tool to perform systematic analysis of threat modeling for CPS is proposed. A real-world wireless railway temperature monitoring system is used as a case study to validate the proposed approach. The threats identified in the system are subsequently mitigated using National Institute of Standards and Technology (NIST) standards.
Keywords: condition monitoring; object-oriented programming; railway engineering; security of data; wireless sensor networks; CPS; NIST standards; National Institute of Standards and Technology; computational component; cyber-physical systems; networking component; physical component; real-world wireless railway temperature monitoring system; systematic potential threat identification; systematic threat modeling approach; Adaptation models; Analytical models; Data models; Security; Software; Systematics; Unified modeling language; Case Study; Cyber-Physical Systems; Systematic Analysis; Threat Modeling (ID#: 16-11030)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7287428&isnumber=7287407
A. Astarloa, N. Moreira, J. Lázaro, M. Urbina and A. Garcia, “1588-Aware High-Availability Cyber-Physical Production Systems,” Precision Clock Synchronization for Measurement, Control, and Communication (ISPCS), 2015 IEEE International Symposium on, Beijing, 2015, pp. 25-30. doi: 10.1109/ISPCS.2015.7324675
Abstract: In this paper an architecture for High-Availability Cyber-Physical Production Systems with sub-microsecond synchronization capabilities is presented. The proposed CPPS nodes are based on cost-affordable components. These CPPS can deal with most of the challenges set by Industry for a massive adoption of the distributed computing philosophy in critical systems like Smart-Grids or Advanced Manufacturing Plants. In order to measure the resilience and accuracy of the 1588-aware high-availability network composed by these nodes, a concept-proof experimental setup has been developed. As it has been verified, although in a case of network failure, the synchronization recovers automatically and the offset between the master's and slaves' PPS signals is maintained below 1 μs.
Keywords: computer aided manufacturing; computer networks; production engineering computing;1588-aware high-availability cyber-physical production systems; CPPS nodes; advanced manufacturing plants; distributed computing philosophy; smart-grids; submicrosecond synchronization; IP networks; Industries; Peer-to-peer computing; Ports (Computers); Sensors; Switches; Synchronization; Cyber-Physical Systems; Cyber-physical Production Systems; FPGA; High-availability Seamless Redundancy (HSR); IEC 61850; IEC 62439; IEC 62439-3-5; IEEE 1588; Industrie 4.0; Precise Time Protocol; Sensors Networks (ID#: 16-11031)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7324675&isnumber=7324666
B. Kantarci, “Cyber-Physical Alternate Route Recommendation System for Paramedics in an Urban Area,” Wireless Communications and Networking Conference (WCNC), 2015 IEEE, New Orleans, LA, 2015, pp. 2155-2160. doi: 10.1109/WCNC.2015.7127801
Abstract: Intelligent transportation systems aim at the betterment of the transportation in cooperation with the Information and Communication Technologies (ICTs). Besides, cyber-physical solutions have enabled interaction between the physical and computational components of systems. This paper studies the route selection of paramedics by the assistance of a cyber-physical system which consists of vehicular communications, alternate route optimization and user interaction components. To this end, an optimal alternate routing-tree recommendation framework is proposed by adopting the minimum Steiner tree approach. Initially the mathematical model is presented and is solved as a Mixed Integer Linear Programming (MILP) formulation. Then, in order to assure fast and efficient solution, simulated annealing-based alternate routing-tree recommendation is proposed for paramedics. Through simulations, the proposed approach is shown to be capable of guaranteeing alternate route selection for paramedics with low-delay, low-cost and high resilience.
Keywords: integer programming; intelligent transportation systems; linear programming; medical computing; mobile computing; recommender systems; simulated annealing; trees (mathematics); vehicle routing; vehicular ad hoc networks; ICTs; MILP formulation; alternate route optimization; cyber-physical alternate route recommendation system; information and communication technologies; intelligent transportation systems; mathematical model; minimum Steiner tree approach; mixed integer linear programming; paramedics route selection; simulated annealing-based alternate routing-tree recommendation; urban area; user interaction components; vehicular communications; Annealing; Conferences; Delays; Global Positioning System; Roads; Simulated annealing; Vehicles; Cyber-physical systems; routing; vehicular networks (ID#: 16-11032)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7127801&isnumber=7127309
W. Chipman, C. Grimm and C. Radojicic, “Coverage of Uncertainties in Cyber-Physical Systems,” ZuE 2015; 8. GMM/ITG/GI-Symposium Reliability by Design; Proceedings of, Siegen, Germany, 2015, pp. 1-8. doi: (not provided)
Abstract: Cyber-physical systems (CPS) consist of software systems and the physical entities that the software controls. CPS have become ubiquitous; the systems can be found in diverse environments. Because of the multitude of components, failures, changes or inaccuracies are inevitable but with the multitude of components also comes the ability to build resilience into the system. An unfortunate side-effect of this resiliency is the addition of unforeseen changes and deviations to the behavior of the system. Many of these cyber-physical systems (CPS) control or contribute significantly to the control of critical systems. In order to achieve first 'time right' system deployment, the accuracy of the models, and the validation of the application fitness is at least as important as the CPS modeling and accuracy. In this paper we discuss and give an overview of methods that strive for validation of CPS systems with increased coverage. In particular, we focus on modeling, verification and validation of uncertainties both known and unknown.
Keywords: (not provided) (ID#: 16-11033)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7348519&isnumber=7348508
P. E. Veríssimo, “MB4CP 2015 Keynote II: Resilience of Cyber-Physical Energy Systems,” Dependable Systems and Networks Workshops (DSN-W), 2015 IEEE International Conference on, Rio de Janeiro, 2015, pp. 3-3. doi: 10.1109/DSN-W.2015.42
Abstract: Electrical utility infrastructures have become largely computerized, remotely/automatically controlled, and interconnected, amongst each other and with other types of critical infrastructures, and we are witnessing the explosion of new paradigms: distributed generation, smart grids. In this accelerated mutation of power grids to cyber-physical systems, may it be that some things are “lost in translation”? Are we using the right models to represent, design, build and analyze cyber physical energy systems? Especially when what used to be an electrical infrastructure became quite susceptible to computer-borne problems such as digital accidental faults and malicious cyber-attacks? This talk will challenge the audience with some reflections and points for discussion along these topics.
Keywords: distributed power generation; electricity supply industry; smart power grids; cyber-physical energy systems; distributed generation; electrical utility infrastructures; power grids; smart grids; Computational modeling; Conferences; Distributed power generation; Explosions; Resilience; Security; Smart grids (ID#: 16-11034)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7272543&isnumber=7272533
Z. Li and R. Kang, “Strategy for Reliability Testing and Evaluation of Cyber Physical Systems,” Industrial Engineering and Engineering Management (IEEM), 2015 IEEE International Conference on, Singapore, 2015, pp. 1001-1006. doi: 10.1109/IEEM.2015.7385799
Abstract: Internal and external factors that influence reliability of CPSs are analyzed in this paper. A strategy for reliability testing and evaluation of CPSs is put forward in the consideration of these factors, including the technology framework and processes. The main work comprises the testing and evaluation of component reliability covering hardware, software, and architecture, as well as the performance reliability including service reliability, cyber security reliability, resilience & elasticity reliability and vulnerability reliability. To give a general look of the system reliability, the four indices of performance reliability are synthesized by the multi-index method. The strategy proposed in the paper will make a great contribution to the complete, dynamic and continuous testing and evaluation for the CPS.
Keywords: cyber-physical systems; program testing; security of data; software reliability; CPS reliability testing; component reliability; cyber security reliability; elasticity reliability; multiindex method; performance reliability; service reliability; vulnerability reliability; Hardware; Reliability theory; Resilience; Software; Software reliability; Testing; Cyber Physical Systems; Evaluation; Reliability; Strategy; Testing (ID#: 16-11035)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7385799&isnumber=7385591
C. Aduba and C. h. Won, “Resilient Cumulant Game Control for Cyber-Physical Systems,” Resilience Week (RWS), 2015, Philadelphia, PA, 2015, pp. 1-6. doi: 10.1109/RWEEK.2015.7287422
Abstract: In this paper, we investigate the resilient cumulant game control problem for a cyber-physical system. The cyberphysical system is modeled as a linear hybrid stochastic system with full-state feedback. We are interested in 2-player cumulant Nash game for a linear Markovian system with quadratic cost function where the players optimize their system performance by shaping the distribution of their cost function through cost cumulants. The controllers are optimally resilient against control feedback gain variations.We formulate and solve the coupled first and second cumulant Hamilton-Jacobi-Bellman (HJB) equations for the dynamic game. In addition, we derive the optimal players strategy for the second cost cumulant function. The efficiency of our proposed method is demonstrated by solving a numerical example.
Keywords: Markov processes; game theory; optimisation; security of data; HJB equation; Hamilton-Jacobi-Bellman equation; Nash game; control feedback gain variation; cumulant game control resiliency; cyber-physical system; full-state feedback; linear Markovian system; linear hybrid stochastic system; quadratic cost function optimization; security vulnerability; Cost function; Cyber-physical systems; Games; Mathematical model; Nash equilibrium; Trajectory (ID#: 16-11036)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7287422&isnumber=7287407
A. Dayal, A. Tbaileh, Y. Deng and S. Shukla, “Distributed VSCADA: An Integrated Heterogeneous Framework for Power System Utility Security Modeling and Simulation,” Modeling and Simulation of Cyber-Physical Energy Systems (MSCPES), 2015 Workshop on, Seattle, WA, 2015, pp. 1-6. doi: 10.1109/MSCPES.2015.7115408
Abstract: The economic machinery of the United States is reliant on complex large-scale cyber-physical systems which include electric power grids, oil and gas systems, transportation systems, etc. Protection of these systems and their control from security threats and improvement of the robustness and resilience of these systems, are important goals. Since all these systems have Supervisory Control and Data Acquisition (SCADA) in their control centers, a number of test beds have been developed at various laboratories. Usually on such test beds, people are trained to operate and protect these critical systems. In this paper, we describe a virtualized distributed test bed that we developed for modeling and simulating SCADA applications and to carry out related security research. The test bed is a virtualized by integrating various heterogeneous simulation components. This test bed can be reconfigured to simulate the SCADA of a power system, or a transportation system or any other critical systems, provided a back-end domain specific simulator for such systems are attached to it. In this paper, we describe how we created a scalable architecture capable of simulating larger infrastructures and by integrating communication models to simulate different network protocols. We also developed a series of middleware packages that integrates various simulation platforms into our test bed using the Python scripting language. To validate the usability of the test bed, we briefly describe how a power system SCADA scenario can be modeled and simulated in our test bed.
Keywords: SCADA systems; authoring languages; control engineering computing; middleware; power system security; power system simulation; Python scripting language; back-end domain specific simulator; complex large-scale cyber-physical systems; distributed VSCADA; economic machinery; heterogeneous simulation components; integrated heterogeneous framework; middleware packages; network protocols; power system utility security modeling; power system utility security simulation platform; supervisory control and data acquisition; system protection; transportation system; virtualized distributed test bed; Databases; Load modeling; Power systems; Protocols; Servers; Software; Cyber Physical Systems; Cyber-Security; Distributed Systems; NetworkSimulation; SCADA (ID#: 16-11037)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7115408&isnumber=7115373
A. Dayal, Yi Deng, A. Tbaileh and S. Shukla, “VSCADA: A Reconfigurable Virtual SCADA Test-Bed for Simulating Power Utility Control Center Operations,” Power & Energy Society General Meeting, 2015 IEEE, Denver, CO, 2015, pp. 1-5. doi: 10.1109/PESGM.2015.7285822
Abstract: Complex large-scale cyber-physical systems, such as electric power grids, oil & gas pipeline systems, transportation systems, etc. are critical infrastructures that provide essential services for the entire nation. In order to improve systems' security and resilience, researchers have developed many Supervisory Control and Data Acquisition (SCADA) test beds for testing the compatibility of devices, analyzed the potential cyber threats/vulnerabilities, and trained practitioners to operate and protect these critical systems. In this paper, we describe a new test bed architecture for modeling and simulating power system related research. Since the proposed test bed is purely software defined and the communication is emulated, its functionality is versatile. It is able to reconfigure virtual systems for different real control/monitoring scenarios. The unified architecture can seamlessly integrate various kinds of system-level power system simulators (real-time/non real-time) with the infrastructure being controlled or monitored with multiple communication protocols. We depict the design methodology in detail. To validate the usability of the test bed, we implement an IEEE 39-bus power system case study with a power flow analysis and dynamics simulation mimicking a real power utility infrastructure. We also include a cascading failure example to show how system simulators such as Power System Simulator for Engineering (PSS/E), etc. can seamlessly interact with the proposed virtual test bed.
Keywords: SCADA systems; critical infrastructures; electricity supply industry; power system control; power system security; power system simulation; protocols; reconfigurable architectures; IEEE 39-bus power system; SCADA; communication protocol; complex large scale cyber-physical system; critical infrastructure; potential cyber threat; power system modelling; power utility control center operation simulation; reconfigurable virtual SCADA test bed architecture; reconfigure virtual system; supervisory control and data acquisition; system level power system simulation; system resilience; system security improvement; vulnerabilities; Computer architecture; Power system dynamics; Protocols; Servers; Software; Cyber Physical Systems; Supervisory Control and Data Acquisition (SCADA) Systems; System Integration; Virtual Test bed (ID#: 16-11038)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7285822&isnumber=7285590
T. Gamage, G. Zweigle, M. Venkathasubramanian, C. Hauser and D. Bakken, “Towards Grid Resilience: A Proposal for a Progressive Control Strategy,” Green Technologies Conference (GreenTech), Proceeding of the 2015 Seventh Annual IEEE, New Orleans, LA, 2015, pp. 58-65. doi: 10.1109/GREENTECH.2015.25
Abstract: This white paper describes preliminary research on the use of progressive control strategies to improve the advanced electric power grid's resilience to major grid disturbances. The proposed approach calls to leverage real-time wide-area monitoring and control capabilities to provide globally coordinated distributed control actions under stressed conditions. To that end, the paper illustrates the proposed concept using case studies drawn from major North American blackouts, discusses design challenges, and proposes the design of a Grid Integrity Management System (GIMS) to manage the required communication and computation to meet these challenges.
Keywords: power grids; power system control; power system faults; power system measurement; power system reliability; GIMS; North American blackouts; electric power grid resilience; grid disturbance; grid integrity management system; progressive control strategy; wide area monitoring; Generators; Load modeling; Monitoring; Power system stability; Real-time systems; Stability analysis; QoS; RAS; cyber-physical systems; distributed control; model predictive control; security; smart grid (ID#: 16-11039)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7150230&isnumber=7150207
C. Z. Bai, F. Pasqualetti and V. Gupta, “Security in Stochastic Control Systems: Fundamental Limitations and Performance Bounds,” American Control Conference (ACC), 2015, Chicago, IL, 2015, pp. 195-200. doi: 10.1109/ACC.2015.7170734
Abstract: This work proposes a novel metric to characterize the resilience of stochastic cyber-physical systems to attacks and faults. We consider a single-input single-output plant regulated by a control law based on the estimate of a Kalman filter. We allow for the presence of an attacker able to hijack and replace the control signal. The objective of the attacker is to maximize the estimation error of the Kalman filter - which in turn quantifies the degradation of the control performance - by tampering with the control input, while remaining undetected. We introduce a notion of ε-stealthiness to quantify the difficulty to detect an attack when an arbitrary detection algorithm is implemented by the controller. For a desired value of ε-stealthiness, we quantify the largest estimation error that an attacker can induce, and we analytically characterize an optimal attack strategy. Because our bounds are independent of the detection mechanism implemented by the controller, our information-theoretic analysis characterizes fundamental security limitations of stochastic cyber-physical systems.
Keywords: Kalman filters; stochastic systems; ε-stealthiness notion; Kalman filter estimation; arbitrary detection algorithm; control law; control performance; estimation error; optimal attack strategy; single-input single-output plant; stochastic control systems; stochastic cyber-physical systems; Cyber-physical systems; Degradation; Detectors; Estimation error; Random sequences; Upper bound
(ID#: 16-11040)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7170734&isnumber=7170700
C. Cheh, G. A. Weaver and W. H. Sanders, “Cyber-Physical Topology Language: Definition, Operations, and Application,” Dependable Computing (PRDC), 2015 IEEE 21st Pacific Rim International Symposium on, Zhangjiajie, 2015, pp. 60-69. doi: 10.1109/PRDC.2015.20
Abstract: Maintaining the resilience of a large-scale system requires an accurate view of the system's cyber and physical state. The ability to collect, organize, and analyze state central to a system's operation is thus important in today's environment, in which the number and sophistication of security attacks are increasing. Although a variety of “sensors” (e.g., Intrusion Detection Systems, log files, and physical sensors) are available to collect system state information, it's difficult for administrators to maintain and analyze the diversity of information needed to understand a system's security state. Therefore, we have developed the Cyber-Physical Topology Language (CPTL) to represent and reason about system security. CPTL combines ideas from graph theory and formal logics, and provides a framework to capture relationships among the diverse types of sensor information. In this paper, we formally define CPTL as well as operations on CPTL models that can be used to infer a system's security state. We then illustrate the use of CPTL in both the enterprise and electrical power domains and provide experimental results that illustrate the practicality of the approach.
Keywords: cyber-physical systems; formal logic; graph theory; security of data; CPTL; cyber-physical topology language; electrical power domain; enterprise domain; formal logics; information diversity; large-scale system; security attacks; sensor information; system security; system state information collection; Data models; Databases; Graph theory; Ontologies; Security; Semantics; Sensors; Cyber-Physical Topology Language; description logics; system state; target system model (ID#: 16-11041)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7371849&isnumber=7371833
N. S. V. Rao, C. Y. T. Ma, U. Shah, J. Zhuang, F. He and D. K. Y. Yau, “On Resilience of Cyber-Physical Infrastructures Using Discrete Product-Form Games,” Information Fusion (Fusion), 2015 18th International Conference on, Washington, DC, 2015,
pp. 1451-1458. doi: (not provided)
Abstract: In critical infrastructures consisting of discrete cyber and physical components, the correlations between them may be exploited to launch strategic component attacks that may degrade the entire system. We capture such correlations between cyber and physical sub-infrastructures using the conditional probabilities, and between cyber and physical components using first-order differential conditions. By using a resilience measure specified by the infrastructure's survival probability, we formulate a discrete game between the provider and attacker. Their disutility functions are products of the survival (or failure) probability and cost terms expressed in terms of the number of components attacked and reinforced by the attacker and provider, respectively. The Nash Equilibrium conditions of the game provide the sensitivity functions that clearly show the dependence of the infrastructure resilience on cost terms, correlation function and sub-infrastructure survival probabilities. These results for product-form disutility functions complement the sum-form results from previous works, and more closely represent the provider's objectives for a certain class of infrastructures. We apply these results to simple models of network testbed infrastructures and cyber infrastructures of smart energy grids.
Keywords: critical infrastructures; game theory; probability; sensitivity; Nash Equilibrium conditions; conditional probabilities; critical infrastructures; cyberphysical infrastructures; discrete cyber components; discrete physical components; discrete product-form games; disutility functions; first-order differential conditions; infrastructure survival probability; network testbed infrastructures; product-form disutility functions; smart energy grids; strategic component attacks; subinfrastructure survival probabilities; Correlation; Games; Mathematical model; Nash equilibrium; Probability; Sensitivity; Smart grids (ID#: 16-11042)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7266728&isnumber=7266535
S. S. Shah and R. F. Babiceanu, “Resilience Modeling and Analysis of Interdependent Infrastructure Systems,” Systems and Information Engineering Design Symposium (SIEDS), 2015, Charlottesville, VA, 2015, pp. 154-158. doi: 10.1109/SIEDS.2015.7116965
Abstract: The infrastructures on which our society depends are interconnected and interdependent on multiple levels. The failure of one infrastructure can result in the disruption of other infrastructures, which can lead to severe economic disruption and loss of life or failure of services. Today, within the cyber-physical engineering and social world, all acting infrastructure systems are certain to be subjected to changes in their environment given by changing inputs, constraints, mechanisms, or interfaces. Moreover, when the infrastructures are interconnected the changes may impact not only the output of individual infrastructures, but also the output of the resulting coordinated operations. This work addresses the concept of resilience of interdependent infrastructures systems and compares the resultant system level resilience with component infrastructure systems resilience.
Keywords: health care; network theory (graphs); reliability theory; transportation; health care delivery infrastructure; infrastructure network model; interdependent infrastructure system analysis; resilience modelling; transportation infrastructure; Analytical models; Computational modeling; Logistics; Medical services; Reliability engineering; Resilience; Transportation; Interdependent infrastructures; Network modeling; Resilience analysis (ID#: 16-11043)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7116965&isnumber=7116953
X. Li, J. Wen and E. W. Bai, “Building Energy Forecasting Using System Identification Based on System Characteristics Test,” Modeling and Simulation of Cyber-Physical Energy Systems (MSCPES), 2015 Workshop on, Seattle, WA, 2015, pp. 1-6. doi: 10.1109/MSCPES.2015.7115401
Abstract: Buildings, consuming over 70% of the electricity in the U.S., play significant roles in smart grid infrastructure. The automatic operation of buildings and their subsystems in responding to signals from a smart grid is essential to reduce energy consumption and demand, as well as improve the resilience to power disruptions. In order to achieve such automatic operation, high fidelity and computationally efficiency building energy forecasting models under different weather and operation conditions are needed. Currently, data-driven (black box) models and hybrid (grey box) models are commonly used in model based building control operation. However, typical black box models often require long training period and are bounded to weather and operation conditions during the training period. On the other hand, creating a grey box model often requires long calculation time due to parameter optimization process and expert knowledge during the model structure determining and simplification process. An earlier study by the authors proposed a system identification approach to develop computationally efficient and accurate building energy forecasting models. This paper attempts to extend this early study and to quantitatively evaluate how the most important characteristics of a building energy system: its nonlinearity and response time, affect the system identification process and model accuracy. Two commercial building: a small-size and a medium-size commercial building, with varying chiller nonlinearity, are simulated using EnergyPlus in lieu of real buildings for model development and validation. The system identification method proposed in the early study is applied to these two buildings that have varying nonlinearity and response time. Adaption of the proposed system identification method based on systems' nonlinearity and response time is proposed in this study. The energy forecasting results demonstrate that the adaption is capable of significantly improve the performance of the system identification model.
Keywords: building management systems; building simulation; optimisation; power consumption; power system parameter estimation; smart power grids; EnergyPlus; black box model; building control operation; building energy forecasting; buildings automatic operation; chiller nonlinearity variation; data-driven model; electricity consumption; energy consumption reduction; long training period; parameter optimization process; power disruption resilience improvement; smart grid infrastructure; system characteristics test; system identification process; Buildings; Computational modeling; Forecasting; Predictive models; System identification; Temperature measurement; Time factors; smart grids; building energy modeling; system identification; system nonlinearity; system response time (ID#: 16-11044)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7115401&isnumber=7115373
E. Penera and D. Chasaki, “Packet Scheduling Attacks on Shipboard Networked Control Systems,” Resilience Week (RWS), 2015, Philadelphia, PA, 2015, pp. 1-6. doi: 10.1109/RWEEK.2015.7287421
Abstract: Shipboard networked control systems are based on a distributed control system architecture that provides remote and local control monitoring. In order to allow the network to scale a hierarchical communication network is composed of high speed Ethernet based network switches. Ethernet is the prevalent medium to transfer control data, such as control signals, alarm signal, and sensor measurements on the network. However, communication capabilities bring new security vulnerabilities and make communication links a potential target for various kinds of cyber/physical attacks. The goal of this work is to implement and demonstrate a network layer attack against networked control systems, by tampering with temporal characteristics of the network, leading to time varying delays and packet scheduling abnormalities.
Keywords: computer network security; delay systems; local area networks; networked control systems; scheduling; ships; telecommunication control; time-varying systems; alarm signal; communication capability; communication link; control data; control signal; cyber attack; distributed control system architecture; hierarchical communication network; high speed Ethernet based network switch; network layer attack; packet scheduling abnormality; packet scheduling attack; physical attack; remote and local control monitoring; security vulnerability; sensor measurement; shipboard networked control system; temporal characteristics; time varying delay; Delays; IP networks; Network topology; Networked control systems; Security; Topology (ID#: 16-11045)
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7287421&isnumber=7287407
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