Networked Automation Systems: a new cryptographic scheme

Recently, Real-time Ethernet has become popular communication technology in automation system applications due to its high bandwidth capacity and low market cost. In addition, CC-Link IE Field has been successful in combining the ultra-high speed feature with the large amount of data to be transferred while integrating in field-level industrial communication networks. This protocol also provides a seamless structure that provides the ability to implement a gateway to communicate with different protocols. On the other hand, many devices such as motor driver still apply CAN or serial RS-485 in automation systems, which means that CC-Link IE Field requires time and cost to allow these devices to implement this new protocol. In order to alleviate this problem, this paper proposes a method of designing a gateway for communicating between the CC-Link IE Field and serial RS-485 based protocol to increase the adoption rate of using CC-Link IE Field in automation system networks. This gateway structure was implemented and verified in experiments of using CC-Link IE Field Master to control motor drives, thus supporting the RS-485 communication interface.

It is well known that the modeling issues in Dynamical systems in chemical processes, networked control systems and automation systems are very complex and model may contain subsystems with different delays. Because of the mathematical complexity, the robust control of these types of multiple time delay system is a challenging one. The problem becomes more difficult and complex when the system is having time delays in both the denominator and the numerator. In this paper a new method is proposed for approximating general multiple time delay continuous-time transfer function system with multiple time delays in both the denominator and the numerator to a single input/output delay. Both Single Input Single Output(SISO) and Multi Input Multi Output(MIMO) cases have been considered. In this proposed methodology, the Approximated Generalized Time Moments (AGTM)/ Approximated Generalized Markov Parameter (AGMP) methods are used to transform the multiple time delay system into a single input/output delay system. A Linear Matrix Inequality (LMI) approach is developed for synthesizing robust H∞ control of the approximated time delay system. The efficacy of the proposed method is shown through illustrative examples. It is evident from the simulation results that the approximated system is stable with the proposed LMI H∞ controller.

ABSTRACTCyber-Physical Systems (CPS) are defined as integrations of computation, communication, and control in order to achieve the desired performance of physical processes. Security threats have a high possibility of affecting CPS by several cyber attacks without providing any indication about failure. One important problem, especially in power systems, is the control problem of systems under cyber attacks. In this paper, a secure observer-based controller for discrete-time CPS subject to both cyber (denial of service (DoS) and deception) and physical attacks will be presented. The occurrences of the cyber and physical attacks will be considered as Bernoulli distributed white sequences with variable conditional probabilities. A sufficient condition is first derived under which the observer-based controller is guaranteed to have the desired security level using the stochastic analysis techniques. Then, the observer and controller gains will be designed by solving a linear matrix inequality using YALMIP and MATLAB. Finally, an illustrative example is provided to demonstrate the feasibility of the proposed system.

In the conventional framework for failure diagnosis of partially observed discrete event systems, it is assumed that, for each event, the corresponding output symbol is determined uniquely. However, this assumption does not hold in discrete event systems such as a mobile system, where an output symbol depends on not only an event but also a state at which the event occurs. In this paper, we model such discrete event systems by Mealy automata with nondeterministic output functions, and consider a decentralized failure diagnosis problem that requires any occurrence of a failure should be detected by at least one local diagnoser within a uniformly bounded number of steps. We present a necessary and sufficient condition for the existence of a decentralized diagnoser. We then present an algorithm for verifying this condition. Moreover, we present a method for synthesizing local online diagnosers.

This paper presents a novel approach to evaluate the response time in networked automation systems (NAS) that use a client/server protocol. The developments introduced are derived from modeling the entire architecture in the form of timed event graphs (TEGs), as well as from the resulting state representation in Max-Plus algebra. The various architectural stages are actually modeled in a very abstract pattern, which yields just those TEG models where local delays are sufficient to perform the overall evaluation. In this manner, linear Max-Plus equations are obtained. A thorough analysis of these equations has led to analytical formulas for direct calculus of NAS response time. As a final step, experimental measurements taken on a laboratory facility have been used to verify the validity of the results. In conclusion, the benefit and effectiveness of this novel method have been demonstrated.

Industrial communication networks have attracted much attention in the area of decentralized control systems for factory automation and computer integrated manufacturing. This paper investigates the rate-based traffic control of industrial communication networks employing LonWorks to improve the performance measures of throughput, fairness and error rates. For this purpose, we utilized feedback channel information through an additional network-monitoring node and made the overall system closed-loop. We demonstrate an improved performance of the controlled network system through experimentation upon an implemented lab-scale network system.

The paper discusses the automated systems (AS) control the use of resources of the object and the scheme of classification of such systems based on the analysis of their drawbacks and advantages. Automated control systems cover a variety of objects in nature, construction, structure and content. This explains the complexity of the unification of all automated systems into a single structure. At present there is no approved universal classification of automated control systems. Existing classifications are based on the properties and characteristics of the systems themselves. This classification does not give a complete picture of their organization, integration with other subsystems, evaluation and analysis of the effectiveness of their implementation of such systems. They contain information about the narrow scope of implementation of automated systems for monitoring resources such as: the level or scope of activities, level of automation and control processes, the degree of centralization of information processing and integration functions. For different companies for each service sector typically develop their own automated system. Such systems should include analysis, collection and processing of information about the object and systems associated with it. In the process of implementing such systems raises the question of resource provision of special equipment, which could ensure the functioning of the system without error during the collection of the information because it has to happen constantly. The proposed classification structure automated systems created on the basis of their weaknesses and strengths creates opportunity for extended evaluation of the effectiveness of their implementation in the enterprise, offices, factories and other facilities. Key words: automated control system, advantages, disadvantages, classification of automated systems.

The article analyzes the existing legal mechanisms for managing critical information infrastructure in Ukraine. The instruments for their improvement are proposing in this article. An important component of critical infrastructure is its information component – a critical information infrastructure. The sphere of protection of critical information infrastructure in Ukraine is at the initial stage of formation. The current legislation defines only certain objects of socio-economic sphere, in which extraordinary events can lead to socially dangerous consequences. In view of the fact, that the term “critical information infrastructure” does not having a consistent interpretation in different countries, we propose our opinion. “Critical information infrastructure is a system of information management of critical facilities and information and communication networks that provide defense capabilities and security of public and private institutions, whose operation may flow to the national security of Ukraine” (KII). In the KII we can identified information and network components. Information environment of KII is a system for information management of critical objects, including computing and information resources that form automated control systems (ACS). The network component of KII consists of a set of telecommunication devices, communication lines and network equipment, systems of open protocols for the exchange of information between elecommunication devices, global system of digital addresses and digital identifiers, software. The Internet network can be considered as a technological add-on over a telecommunication network that provides the provision of data transmission and processing services (e-mail, teleconferencing, file transfer, access to computing and information systems in local area networks). The main threat to the safety of ACS of critical information infrastructure objects is targeted actions on information systems, information and telecommunication networks by software and hardware. KII legal security include two main components – national and international. The national component may be forming by a set of principles, legal institutions and norms, which are enshrined in the national legislation regulating public relations in Ukraine in the area of counteracting the security threats of the ACS of critical objects. In order to protect the most important objects of KII, it is necessary to identify these objects. The current legislation defines such categories of objects, for which special conditions for ensuring their protection and functioning are established. Some of them, in whole or in part, may be classifying as objects of critical infrastructure. The specificity of providing information security was reflecting in such Ukraine laws like “On the Fundamentals of National Security of Ukraine”, “On the Concept of the National Program of Informatization”, “On the National Program of Informatization”. As well as the Concept of Development of the Security and Defense Sector of Ukraine, the National Security Strategy of Ukraine, the Strategy of Cybersecurity Of Ukraine. The National Security Strategy identifies actual threats to national security and sets priorities for information security, cyber security and security of information resources and critical infrastructure. At the same time, the implementation of the state policy in the field of security of KII requires the further development of legal principles and norms governing the relevant social relations, that is, the national component of the legal security of KII. Ukraine should ensure the establishment of a nationwide system for assessing risks and threats to critical infrastructure, and after the legislative definition of the main terms, the implementation of the Identification of Critical Information Infrastructure objects. Identification of objects of critical information infrastructure can be accomplishing by introducing the certification of objects of critical information infrastructure. Such passports must contain general data about the facility, data on the main sources of danger, data on hazardous natural conditions, technological processes and response to threats. The international component of the legal security of KII provides for the regulation of a set of principles and norms defined by international treaties and recognized by the state, regulating issues of international cooperation in this area. Ukraine has signed the Convention on Cybercrime together with the member states of the Council of Europe and other States. It is aiming at stopping actions against the confidentiality, integrity and availability of computer systems, networks and computer data, as well as abusing such systems, networks and data by installing the criminal responsibility for such behavior, the provision of powers sufficient to combat criminal offenses, and the conclusion of agreements on rapid and reliable international cooperation. In addition, the plan of measures for 2017 on implementation of the Cybersecurity Strategy of Ukraine provides for the implementation of Directive 2008/114/EC on the protection of critical infrastructure, in particular on cybersecurity and cyber defense of critical infrastructure objects. Development of the system of international information security, the following main groups of international relations that requirenormative legal regulation within the framework of the legal security of KII: definition of the boundaries of the national KII in the global information and communication infrastructure and fixing signs of computer incidents in the control system of critical objects information infrastructure. The absence of generally recognized borders of state sovereignty of States in this space is a significant obstacle to the application of international law to the actions of other states. In particular, this impedes the establishment of limits of responsibility of states for violating the security of the KII and organizing international cooperation in the field of countering computer crime. The urgency of the legislative consolidation of signs of computer incidents in the automated control system of critical information infrastructure objects suggests the widespread use of the concept of “incident” in international law. An incident in cyberspace usually associated with a violation of the functioning of the components of cyberspace – an electronic collection environment and automated processing of information that determines the processes of the implementation of these operations, as well as information systems and automated control systems. The essence of the general definition of the “international incident” in the field of KII will be determining, firstly, by the nature of international relations between states that are violating by the “incident”. This event may be the result of unforeseen actions of the state, including actions that harm the interests of public bodies of one or more states, or, conversely, be one of many intentional but minor provocations carried out by agents of one state against another state. Given that international relations in the field of incidents in the field of KII are not regulating by international treaties, the main and, in fact, the only source of international law in this case serves as an international custom, however, its application to the sphere of KII is accompanying by considerable difficulties. For Ukraine, it is possible to introduce the positive experience of other states in the security of the KII. In particular, the problem of security of information technologies has been enshrined in the international standard ISO / IEC 15408 “General criteria for assessing the safety of information technology”.

In the conventional supervisory control framework for discrete event systems (DESs) with partial event observation, it is assumed that, for each event, the corresponding output symbol is determined uniquely. However, this assumption does not hold in DESs such as a system with sensor errors and a mobile system, where an output symbol depends on not only an event but also a state at which the event occurs. In this technical note, we model such a DES by a Mealy automaton with a nondeterministic output function. We consider a supervisor, called the anti-permissive supervisor, that assigns its control action based on an anti-permissive policy. We introduce a notion of AP-achievability to characterize a class of languages achievable by the anti-permissive supervisor, and discuss the existence of a nonblocking supervisor.

Fault detection and isolation is a crucial and challenging task in the automatic control of large complex systems. We propose a discrete-event system (DES) approach to the problem of failure diagnosis. We introduce two related notions of diagnosability of DES's in the framework of formal languages and compare diagnosability with the related notions of observability and invertibility. We present a systematic procedure for detection and isolation of failure events using diagnosers and provide necessary and sufficient conditions for a language to be diagnosable. The diagnoser performs diagnostics using online observations of the system behavior; it is also used to state and verify off-line the necessary and sufficient conditions for diagnosability. These conditions are stated on the diagnoser or variations thereof. The approach to failure diagnosis presented in this paper is applicable to systems that fall naturally in the class of DES's; moreover, for the purpose of diagnosis, most continuous variable dynamic systems can be viewed as DES's at a higher level of abstraction.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

An awareness of failure type and location is an indispensable requirement for the establishment of adequate recovery strategies and the maintenance of Factory Automation and Process Control systems. The failure diagnosis methodology presented in this paper is based on Discrete Event Systems models and in the diagnoser concept, which enable the off-line and on-line analysis of systems failures. We present an approach for models and associated diagnosers based on a modular decomposition of the global system, with the aim of avoiding problems of exponential explosion in the number of states and computational complexity of the diagnosis process.

Classical control technology has by and large focused on continuous-time systems???-???including their digitized and sampled equivalents. The unequivocal success in this arena has resulted in a broadening of interests and in explorations of the application of control concepts to other problems, even those that are not readily amenable to the techniques of traditional control. This chapter focuses on one such topic: discrete-event systems. Whereas control technology is mostly concerned with systems with internal dynamics that can be mediated by continuous-valued inputs, discrete-event systems (DES) exhibit dynamics that evolve in accordance with external events???-???the state of the system changes only when an event occurs. Many problems in communication networks, manufacturing systems, transportation and traffic, and numerous other domains can be seen as DES applications. In the first case, for example, events of interest can be the arrival of packets of information at a node in the network. (Connections between DES and communication networks are further elaborated in Chapter 19.) Modeling approaches for DES include state machines and automata, Markov chains, and timed models using event clocks. Simple examples are shown for each, drawn from computer systems with on, off, and failed states and single-server queues. Some of these models are also discussed in Chapter 7 which deals with systems that combine discrete-event and continuous-time dynamics. This chapter also discusses the topic of optimization of DESs: how control parameters of a DES (for example, the mean service time for jobs in a queue) can be selected to optimize some performance measure. To use gradient-based optimization methods for discrete-event systems, gradient information must be estimated; since the systems and their representations are not continuous, gradients cannot be analytically calculated. Stochastic approximation algorithms are an effective option and can even allow DES optimization to be performed on-line, while the system is operating.

This paper investigates the controller design problem of networked control systems subject to cyber attacks. A hybrid-triggering communication strategy is employed to save the limited communication resources. State measurements are transmitted over a communication network and may be corrupted by cyber attacks. The aim of this paper is to design a controller for a new closed-loop system model with consideration of randomly occurring cyber attacks and the hybrid-triggering scheme. A stability criterion is obtained for the system stabilization by employing Lyapunov stability theory and stochastic analysis techniques. Moreover, the desired controller gain is derived by resorting to some matrix inequalities. Finally, a numerical example is exploited to demonstrate the usefulness of the proposed scheme.

The modern industrial communication networks are increasingly based on open protocols and various platforms, which are used in the IT (Information Technology) office and the Internet In general, for the TCP/IP protocol suite, a wide range of cryptography-based secure communication now is available. In automation and control systems, which have a number of security relevant characteristics distinct from the IT office, the data transmission may not strictly require. However, data and user authentication as well as access control are crucial for the mission critical and safety critical operation of the automation systems. To mark them, this paper describes the status of relevant specifications and implementations for a number of the standardized automation protocols that is based on OPC techniques. Moreover, this paper provides more security solutions that are proposed and applied in control and monitoring systems to ensure solving system requirements such as optimal performance, system safety, and the ability of preventing the attackers. Besides, this paper also provides more open issues for researching and proposing the optimal security solutions to apply into real industrial systems.

The ongoing integration of various devices and services into nowadays buildings as part of networked building automation systems (BAS) demands for flexible and dynamically adaptable system architectures as they are supported by service orientation, which, moreover, can provide suitable abstractions when integrating new technologies and systems arising for example from the Internet of Things. The increasing complexity of such service systems, however, is accompanied by increasing dependability requirements. Therefore a comprehensive and automated technical management system including service lifecycle management, dynamic (re-)configuration, distributed (re-)deployment, self-repair etc. has to be accomplished. Furthermore the management tasks and the required abstraction of the managed system should span a defined state space in order to enable formal verification of system characteristics like dependability. This work reports on a technical management system utilizing general and system-specific event-condition-action-rules (ECA rules) to enable the dependable operation of BAS. The management tree does not only serve as homogeneous management interface to the BAS, but spans in conjunction with the ECA rules the desired state space.