Showing papers on "Cyber-physical system published in 2013"

Attack Detection and Identification in Cyber-Physical Systems

Abstract: Cyber-physical systems are ubiquitous in power systems, transportation networks, industrial control processes, and critical infrastructures. These systems need to operate reliably in the face of unforeseen failures and external malicious attacks. In this paper: (i) we propose a mathematical framework for cyber-physical systems, attacks, and monitors; (ii) we characterize fundamental monitoring limitations from system-theoretic and graph-theoretic perspectives; and (ii) we design centralized and distributed attack detection and identification monitors. Finally, we validate our findings through compelling examples.

Introduction to Embedded Systems - A Cyber-Physical Systems Approach

Abstract: The most visible use of computers and software is processing information for human consumption. The vast majority of computers in use, however, are much less visible. They run the engine, brakes, seatbelts, airbag, and audio system in your car. They digitally encode your voice and construct a radio signal to send it from your cell phone to a base station. They command robots on a factory floor, power generation in a power plant, processes in a chemical plant, and traffic lights in a city. These less visible computers are called embedded systems, and the software they run is called embedded software. The principal challenges in designing and analyzing embedded systems stem from their interaction with physical processes. This book takes a cyber-physical approach to embedded systems, introducing the engineering concepts underlying embedded systems as a technology and as a subject of study. The focus is on modeling, design, and analysis of cyber-physical systems, which integrate computation, networking, and physical processes. The second edition offers two new chapters, several new exercises, and other improvements. The book can be used as a textbook at the advanced undergraduate or introductory graduate level and as a professional reference for practicing engineers and computer scientists. Readers should have some familiarity with machine structures, computer programming, basic discrete mathematics and algorithms, and signals and systems.

Cyber-Physical Security Testbeds: Architecture, Application, and Evaluation for Smart Grid

Abstract: The development of a smarter electric grid will depend on increased deployments of information and communication technology (ICT) to support novel communication and control functions. Unfortunately, this additional dependency also expands the risk from cyber attacks. Designing systems with adequate cyber security depends heavily on the availability of representative environments, such as testbeds, where current issues and future ideas can be evaluated. This paper provides an overview of a smart grid security testbed, including the set of control, communication, and physical system components required to provide an accurate cyber-physical environment. It then identifies various testbed research applications and also identifies how various components support these applications. The PowerCyber testbed at Iowa State University is then introduced, including the architecture, applications, and novel capabilities, such as virtualization, Real Time Digital Simulators (RTDS), and ISEAGE WAN emulation. Finally, several attack scenarios are evaluated using the testbed to explore cyber-physical impacts. In particular, availability and integrity attacks are demonstrated with both isolated and coordinated approaches, these attacks are then evaluated based on the physical system's voltage and rotor angle stability.

Cloud-Based Software Platform for Big Data Analytics in Smart Grids

Abstract: This article focuses on a scalable software platform for the Smart Grid cyber-physical system using cloud technologies Dynamic Demand Response (D2R) is a challenge-application to perform intelligent demand-side management and relieve peak load in Smart Power Grids The platform offers an adaptive information integration pipeline for ingesting dynamic data; a secure repository for researchers to share knowledge; scalable machine-learning models trained over massive datasets for agile demand forecasting; and a portal for visualizing consumption patterns, and validated at the University of Southern California's campus microgrid The article examines the role of clouds and their tradeoffs for use in the Smart Grid Cyber-Physical Sagileystem

The Future of Human-in-the-Loop Cyber-Physical Systems

Abstract: A prototyping platform and a design framework for rapid exploration of a novel human-in-the-loop application serves as an accelerator for new research into a broad class of systems that augment human interaction with the physical world.

Security analysis for Cyber-Physical Systems against stealthy deception attacks

Abstract: Security of Cyber-Physical Systems (CPS) against cyber attacks is an important yet challenging problem. Since most cyber attacks happen in erratic ways, it is difficult to describe them systematically. In this paper, instead of identifying a specific cyber attack model, we are focused on analyzing the system's response during cyber attacks. Deception attacks (or false data injection attacks), which are performed by tampering with system components or data, are not of particular concern if they can be easily detected by the system's monitoring system. However, intelligent cyber attackers can avoid being detected by the monitoring system by carefully design cyber attacks. Our main objective is to investigate the performance of such stealthy deception attacks from the system's perspective. We investigate three kinds of stealthy deception attacks according to the attacker's ability to compromise the system. Based on the information about the dynamics of the system and existing hypothesis testing algorithms, we derive the necessary and sufficient conditions under which the attacker could perform each kind of attack without being detected. In the end, we illustrate the threat of these cyber attacks using an Unmanned Aerial Vehicle (UAV) navigation example.

Effect of Intrusion Detection and Response on Reliability of Cyber Physical Systems

Abstract: In this paper we analyze the effect of intrusion detection and response on the reliability of a cyber physical system (CPS) comprising sensors, actuators, control units, and physical objects for controlling and protecting a physical infrastructure. We develop a probability model based on stochastic Petri nets to describe the behavior of the CPS in the presence of both malicious nodes exhibiting a range of attacker behaviors, and an intrusion detection and response system (IDRS) for detecting and responding to malicious events at runtime. Our results indicate that adjusting detection and response strength in response to attacker strength and behavior detected can significantly improve the reliability of the CPS. We report numerical data for a CPS subject to persistent, random and insidious attacks with physical interpretations given.

From machine-to-machine communications towards cyber-physical systems

Abstract: In recent years, cyber-physical systems (CPS) have emerged as a promising direction to enrich the interactions between physical and virtual worlds. In this article, we first present the correlations among machine-to-machine (M2M), wireless sensor networks (WSNs), CPS and internet of things (IoT), and introduce some research activities in M2M, including M2M architectures and typical applications. Then, we review two CPS platforms and systems that have been proposed recently, including a novel prototype platform for multiple unmanned vehicles with WSNs navigation and cyber-transportation systems. Through these reviews, we propose CPS is an evolution of M2M by the introduction of more intelligent and interactive operations, under the architecture of IoT. Also, we especially hope to demonstrate how M2M systems with the capabilities of decision-making and autonomous control can be upgraded to CPS and identify the important research challenges related to CPS designs.

Vita: A Crowdsensing-Oriented Mobile Cyber-Physical System

Abstract: As a prominent subcategory of cyber-physical systems, mobile cyber-physical systems could take advantage of widely used mobile devices, such as smartphones, as a convenient and economical platform that facilitates sophisticated and ubiquitous mobile sensing applications between humans and the surrounding physical world. This paper presents Vita, a novel mobile cyber-physical system for crowdsensing applications, which enables mobile users to perform mobile crowdsensing tasks in an efficient manner through mobile devices. Vita provides a flexible and universal architecture across mobile devices and cloud computing platforms by integrating the service-oriented architecture with resource optimization mechanism for crowdsensing, with extensive supports to application developers and end users. The customized platform of Vita enables intelligent deployments of tasks between humans in the physical world, and dynamic collaborations of services between mobile devices and cloud computing platform during run-time of mobile devices with service failure handling support. Our practical experiments show that Vita performs its tasks efficiently with a low computation and communication overhead on mobile devices, and eases the development of multiple mobile crowdsensing applications and services. In addition, we present a mobile crowdsensing application, Smart City, developed on Vita to demonstrate the functionalities and practical usage of Vita.

Modeling Cyber-Physical Vulnerability of the Smart Grid With Incomplete Information

Abstract: This paper addresses the attack modeling using vulnerability of information, communication and electric grid network. Vulnerability of electric grid with incomplete information has been analyzed using graph theory based approach. Vulnerability of information and communication (cyber) network has been modeled utilizing concepts of discovery, access, feasibility, communication speed and detection threat. Common attack vector based on vulnerability of cyber and physical system have been utilized to operate breakers associated with generating resources to model aurora-like event. Real time simulations for modified IEEE 14 bus test case system and graph theory analysis for IEEE 118 bus system have been presented. Test case results show the possible impact on smart grid caused by integrated cyber-physical attack.

Parallel scheduling for cyber-physical systems: analysis and case study on a self-driving car

Abstract: As the complexity of software for Cyber-Physical Systems (CPS) rapidly increases, multi-core processors and parallel programming models such as OpenNP become appealing to CPS developers for guaranteeing timeliness. Hence, a parallel task on multi-core processors is expected to become a vital component in CPS such as a self-driving car, where tasks must be scheduled in real-time. In this paper, we extend the fork-join parallel task model to be scheduled in real-time, where the number of parallel threads can vary depending on the physical attributes of the system. To efficiently schedule the proposed task model, we develop the task stretch* transform. Using this transform for global Deadline Monotonic scheduling for fork-join real-time tasks, we achieve a resource augmentation bound of 3.73. In other words, any task set that is feasible on m unit-speed processors can be scheduled by the proposed algorithm on m processors that are 3.73 times faster. The proposed scheme is implemented on Linux/RK as a proof of concept, and ported to Boss, the self-driving vehicle that won the 2007 DARPA Urban Challenge. We evaluate our scheme on Boss by showing its driving quality, i.e., curvature and velocity profiles of the vehicle.

Cyber-physical system design contracts

Abstract: This paper introduces design contracts between control and embedded software engineers for building Cyber-Physical Systems (CPS). CPS design involves a variety of disciplines mastered by teams of engineers with diverse backgrounds. Many system properties influence the design in more than one discipline. The lack of clearly defined interfaces between disciplines burdens the interaction and collaboration. We show how design contracts can facilitate interaction between 2 groups: control and software engineers. A design contract is an agreement on certain properties of the system. Every party specifies requirements and assumptions on the system and the environment. This contract is the central point of inter-domain communication and negotiation. Designs can evolve independently if all parties agree to a contract or designs can be modified iteratively in negotiation processes. The main challenge lies in the definition of a concise but sufficient contract. We discuss design contracts that specify timing and functionality, two important properties control and software engineers have to agree upon. Various design approaches have been established and implemented successfully to address timing and functionality. We formulate those approaches as design contracts and propose guidelines on how to choose, derive and employ them. Modeling and simulation support for the design contracts is discussed using an illustrative example.

A Game-Theoretical Scheme in the Smart Grid With Demand-Side Management: Towards a Smart Cyber-Physical Power Infrastructure

Abstract: The smart grid is becoming one of the fundamental cyber-physical systems due to the employment of information and communication technology. In the smart grid, demand-side management (DSM) based on real-time pricing is an important mechanism for improving the reliability of the grid. Electricity retailers in the smart grid can procure electricity from various supply sources, and then sell it to the customers. Therefore, it is critical for retailers to make effective procurement and price decisions. In this paper, we propose a novel game-theoretical decision-making scheme for electricity retailers in the smart grid using real-time pricing DSM. We model and analyze the interactions between the retailer and electricity customers as a four-stage Stackelberg game. In the first three stages, the electricity retailer, as the Stackelberg leader, makes decisions on which electricity sources to procure electricity from, how much electricity to procure, and the optimal retail price to offer to the customers, to maximize its profit. In the fourth stage, the customers, who are the followers in the Stackelberg game, adjust their individual electricity demand to maximize their individual utility. Simulation results show that the retailer and customers can achieve a higher profit and higher utility using our proposed decision-making scheme. We also analyze how the system parameters affect the procurement and price decisions in the proposed decision-making scheme.

An Online Optimization Approach for Control and Communication Codesign in Networked Cyber-Physical Systems

Abstract: Networked cyber-physical systems (NCPS), where control and communication are closely integrated, have been envisioned to have a large number of high-impact applications In this paper, a joint optimization framework is presented, which combines the objective of control as well as other relevant system objectives and constraints such as communication errors, delays and the limited capabilities (eg, energy capacities) of devices The problem is solved by an online optimization approach, which consists of a communication protocol and a simulated annealing based control algorithm Meanwhile, by taking into account the communication cost, we optimize the control intervals by integrating two kinds of acceptances, ie, cyber and physical acceptances, into the control algorithm Numerical results show the effectiveness of the proposed approach

Cyber Physical System Challenges for Human-in-the-Loop Control

Abstract: This paper articulates three main challenges for employing feedback control with humans in the loop. They are: (i) the need for a comprehensive understanding of the complete spectrum of the types of human-in-the-loop controls, (ii) the need for extensions to system identification or other techniques to derive models of human behaviors, and (iii) most importantly, determining how to incorporate human behavior models into the formal methodology of feedback control.

Resilient control of cyber-physical systems against Denial-of-Service attacks

Abstract: The integration of control systems with modern information technologies has posed potential security threats for critical infrastructures. The communication channels of the control system are vulnerable to malicious jamming and Denial-of-Service (DoS) attacks, which lead to severe time-delays and degradation of control performances. In this paper, we design resilient controllers for cyber-physical control systems under DoS attacks. We establish a coupled design framework which incorporates the cyber configuration policy of Intrusion Detection Systems (IDSs) and the robust control of dynamical system. We propose design algorithms based on value iteration methods and linear matrix inequalities for computing the optimal cyber security policy and control laws. We illustrate the design principle with an example from power systems. The results are corroborated by numerical examples and simulations.

A Framework for Modeling Cyber-Physical Switching Attacks in Smart Grid

Abstract: Security issues in cyber-physical systems are of paramount importance due to the often safety-critical nature of its associated applications. A first step in understanding how to protect such systems requires an understanding of emergent weaknesses, in part, due to the cyber-physical coupling. In this paper, we present a framework that models a class of cyber-physical switching vulnerabilities in smart grid systems. Variable structure system theory is employed to effectively characterize the cyber-physical interaction of the smart grid and demonstrate how existence of the switching vulnerability is dependent on the local structure of the power grid. We identify and demonstrate how through successful cyber intrusion and local knowledge of the grid an opponent can compute and apply a coordinated switching sequence to a circuit breaker to disrupt operation within a short interval of time. We illustrate the utility of the attack approach empirically on the Western Electricity Coordinating Council three-machine, nine-bus system under both model error and partial state information.

S3A: secure system simplex architecture for enhanced security and robustness of cyber-physical systems

Abstract: The recently discovered 'W32.Stuxnet' worm has drastically changed the perception that systems managing critical infrastructure are invulnerable to software security attacks. Here we present an architecture that enhances the security of safety-critical cyber-physical systems despite the presence of such malware. Our architecture uses the property that control systems have deterministic real-time) execution behavior to detect an intrusion within 0.6 μs while still guaranteeing the safety of the plant. We also show that even if an attacker is successful (or gains access to the operating system's administrative privileges), the overall state of the physical system still remains safe.

A Cyber Physical Test-Bed for Virtualization of RF Access Environment for Body Sensor Network

Abstract: Performance evaluation of wireless access and localization is important for body sensor networks, as any defects in the design not only cause wastage of resources, but also threaten an individual's health and safety. The typical cyber methods, however, such as software simulation, often fail to accurately simulate the influence of hardware implementation. The traditional physical methods, however, such as field testing, are not capable of creating repeatable and controllable channel conditions. To combine cyber and physical factors as well as to address the issue, we present a cyber physical test-bed for environment virtualization to facilitate the performance evaluation of wireless access and localization in body sensor networks. This test-bed creates a virtualized environment by emulating the wireless channel in a cybernetic way using a real time channel emulator. The original devices or systems under testing can be physically connected to a channel emulator to evaluate the performance in the virtualization environment. Furthermore, the cyber physical test-bed supports various scenarios from in-body data transmission to time of arrival based indoor localization. To validate the cyber physical approach, emulated outputs are compared with the empirical data obtained from actual measurements. To overcome the bandwidth limitation of traditional digital channel emulators, we have designed an analog channel emulator for UWB technologies. The preliminary verification of this analog emulator is introduced at the end of this paper.

A preliminary cyber-physical security assessment of the Robot Operating System (ROS)

Abstract: Over the course of the last few years, the Robot Operating System (ROS) has become a highly popular software framework for robotics research. ROS has a very active developer community and is widely used for robotics research in both academia and government labs. The prevalence and modularity of ROS cause many people to ask the question: “What prevents ROS from being used in commercial or government applications?” One of the main problems that is preventing this increased use of ROS in these applications is the question of characterizing its security (or lack thereof). In the summer of 2012, a crowd sourced cyber-physical security contest was launched at the cyber security conference DEF CON 20 to begin the process of characterizing the security of ROS. A small-scale, car-like robot was configured as a cyber-physical security “honeypot” running ROS. DEFFCON-20 attendees were invited to find exploits and vulnerabilities in the robot while network traffic was collected. The results of this experiment provided some interesting insights and opened up many security questions pertaining to deployed robotic systems. The Federal Aviation Administration is tasked with opening up the civil airspace to commercial drones by September 2015 and driverless cars are already legal for research purposes in a number of states. Given the integration of these robotic devices into our daily lives, the authors pose the following question: “What security exploits can a motivated person with little-to-no experience in cyber security execute, given the wide availability of free cyber security penetration testing tools such as Metasploit?” This research focuses on applying common, low-cost, low-overhead, cyber-attacks on a robot featuring ROS. This work documents the effectiveness of those attacks.

Self-aware cyber-physical systems and applications in smart buildings and cities

Abstract: The world is facing several challenges that must be dealt within the coming years such as efficient energy management, need for economic growth, security and quality of life of its habitants. The increasing concentration of the world population into urban areas puts the cities in the center of the preoccupations and makes them important actors for the world's sustainable development strategy. ICT has a substantial potential to help cities to respond to the growing demands of more efficient, sustainable, and increased quality of life in the cities, thus to make them "smarter". Smartness is directly proportional with the "awareness". Cyber-physical systems can extract the awareness information from the physical world and process this information in the cyber-world. Thus, a holistic integrated approach, from the physical to the cyber-world is necessary for a successful and sustainable smart city outcome. This paper introduces important research challenges that we believe will be important in the coming years and provides guidelines and recommendations to achieve self-aware smart city objectives.

Future Research on Cyber-Physical Emergency Management Systems

Abstract: Cyber-physical systems that include human beings and vehicles in a built environment, such as a building or a city, together with sensor networks and decision support systems have attracted much attention. In emergencies, which also include mobile searchers and rescuers, the interactions among civilians and the environment become much more diverse, and the complexity of the emergency response also becomes much greater. This paper surveys current research on sensor-assisted evacuation and rescue systems and discusses the related research issues concerning communication protocols for sensor networks, as well as several other important issues, such as the integrated asynchronous control of large-scale emergency response systems, knowledge discovery for rescue and prototyping platforms. Then, we suggest directions for further research.

Cyber Physical System: Architecture, applications and research challenges

Abstract: Cyber world and physical world were considered as two different entities in the past decade. However, researchers have found that these two entities are closely correlated with each other after integration of sensor/actuators in the cyber systems. Cyber systems became responsive to the physical world by enabling real time control emanating from conventional embedded systems, thus emerging a new research paradigm named Cyber Physical System (CPS). In this article, we investigate major challenges in the integration of cyber world with physical world and its applications. In addition, we propose an architecture which contains several modules supporting the CPS. We found that every module in our proposed architecture has its own significance and can be applied to various applications.

EPIC: A Testbed for Scientifically Rigorous Cyber-Physical Security Experimentation

Abstract: Recent malware, like Stuxnet and Flame, constitute a major threat to networked critical infrastructures (NCIs), e.g., power plants. They revealed several vulnerabilities in today's NCIs, but most importantly they highlighted the lack of an efficient scientific approach to conduct experiments that measure the impact of cyber threats on both the physical and the cyber parts of NCIs. In this paper, we present EPIC, a novel cyber-physical testbed, and a modern scientific instrument that can provide accurate assessments of the effects that cyber-attacks may have on the cyber and physical dimensions of NCIs. To meet the complexity of today's NCIs, EPIC employs an Emulab-based testbed to recreate the cyber part of NCIs and multiple software simulators for the physical part. Its main advantage is that it can support very accurate, real-time, repeatable, and realistic experiments with heterogeneous infrastructures. We show through several case studies how EPIC can be applied to explore the impact that cyber-attacks and Information and Communications Technology system disruptions have on critical infrastructures.

Balancing System Survivability and Cost of Smart Grid Via Modeling Cascading Failures

Abstract: As a typical emerging application of cyber physical system, smart power grid is composed of interdependent power grid and communication/control networks. The latter one contains relay nodes for communication and operation centers to control power grid. Failure in one network might cause failures in the other. In addition, these failures may occur recursively between the two networks, leading to cascading failures. We propose a k-to- n interdependence model for smart grid. Each relay node and operation center is supported by only one power station, while each power station is monitored and controlled by k operation centers. Each operation center controls n power stations. We show that the system controlling cost is proportional to k. Through calculating the fraction of functioning parts (survival ratio) using percolation theory and generating functions, we reveal the nonlinear relation between controlling cost and system robustness, and use graphic solution to prove that a threshold exists for the proportion of faulty nodes, beyond which the system collapses. The extensive simulations validate our analysis, determine the percentage of survivals and the critical values for different system parameters. The mathematical and experimental results show that smart grid with higher controlling cost has a sharper transition, and thus is more robust. This is the first paper that focuses on on improving smart power grid robustness by changing monitoring strategies from an interdependent complex networks perspective.

metroII: A design environment for cyber-physical systems

Abstract: Cyber-Physical Systems are integrations of computation and physical processes and as such, will be increasingly relevant to industry and people. The complexity of designing CPS resides in their heterogeneity. Heterogeneity manifest itself in modeling their functionality as well as in the implementation platforms that include a multiplicity of components such as microprocessors, signal processors, peripherals, memories, sensors and actuators often integrated on a single chip or on a small package such as a multi-chip module. We need a methodology, tools and environments where heterogeneity can be dealt with at all levels of abstraction and where different tools can be integrated. We present here Platform-Based Design as the CPS methodology of choice and metroII, a design environment that supports it. We present the metamodeling approach followed in metroII, how to couple the functionality and implementation platforms of CPS, and the simulation technology that supports the analysis of CPS and of their implementation. We also present examples of use and the integration of metroII with another popular design environment developed at Verimag, BIP.

Context-sensitive synthesis of executable functional models of cyber-physical systems

Abstract: The high complexity of cross-domain engineering in combination with the pressure for product innovation, higher quality, time-to-market, and budget constraints make it imperative for companies to use integrated engineering methods and tools. Computer engineering tools are mainly focused on a particular domain and therefore it is difficult to combine different tools for system-level analysis. This paper presents a novel approach and tool for integrated cyber-physical systems (CPS) design based on the FBS (Function-Behavior-State) methodology where multi-domain simulation models capturing both the behavioral-structural aspects of a system are automatically generated from its functional description. Our approach focuses on simulation-enabled FBS models using automatic and context - sensitive mappings of standard Functional Basis elementary functions to simulation components described in physical modeling languages (i.e. Modelica). Using a real electromechanical CPS application we demonstrate how our context-sensitive synthesis approach generates industry-quality executable functional models of higher quality than state-of-the-art approaches using manual mapping.