Design and implementation of computer network security detection and control system

This chapter contains sections titled: Some Terminology on Network Security ISO/OSI Reference Model for Networks Network Security Attacks Mechanisms and Controls for Network Security: Book Overview and Structure References ]]>

Aiming at face Tri-networks integration demand bearing network/core backbone, carry out research of security control technical structure , key technologies and standards systematic In Tri-networks integration environment, to Build a safer control system that includes Facing the Tri-networks integration of business, network, content, behavior, etc. Research oriented business level controls and abnormal behavior of preventing high-speed low delay safety control equipment, builds the control center system, realize the legality of different modal information content safety monitoring control, network security situation analysis and display, control strategy of unified management and dynamic maintenance, and other functions. validation the functions and performance of security control network system, argumentation the feasibility and evolution ability of the fusion network security control system structure.

With the advent of the era of big data, intelligent and Internet +, personnel training and education of the school, the teaching pattern reform needs network information technology to support, so the education organization attaches great importance to the development of network information technology, as one type of higher education in higher vocational colleges, no matter from the education administrative department or local government attaches great importance to the development of higher vocational education, especially for digital campus construction in higher vocational colleges put forward very high requirements. From higher vocational colleges to strengthen the construction of digital campus, strengthen the campus network information security, this paper explores the deficiency existing in digital campus construction, research the connotation of higher vocational digital campus network security prevention and control system clear priorities, further summarizes the work method

The Internet of Things system is a product of the combination of information technology in the rapid development of computer technology, and it is an important foundation for the development of the information age. But we cannot ignore computer network security issues in the application of the Internet of Things. In order to effectively control the security issues of the Internet of Things, we have to study and analyze the potential security risks in the current Internet of Things computer network. In addition, we should explore reliable network security control measures and computer remote control technology. Only in this way can the further development of the IoT system be promoted.

Design, Analysis and Real-time Implementation of Networked Predictive Control Systems

The performance of a networked control system (NCS) is affected directly and indirectly by time delays generated in network communication. This paper addresses these time delays, their effects on system performance and the measures taken in an NCS design. For a time delay that is random but less than one sampling interval T, we model the system as a time-invariant control system with constant time delay T. For a time delay that is random and greater than one sampling interval T, we consider the system as a control system with packet drop and model it as a jump linear control system. Based on the above models, we propose a systematic method to improve the control system quality of performance by choosing a proper sampling interval to reduce data transmission, optimally scheduling to minimise packet loss and optimising controller design in case of packet loss. The simulation results and lab experiments demonstrate that the design method results in high performance in networked real-time control system.

In the past, control system networks were isolated from public external networks, so there was no way to access the control system networks from external networks. Security issues of control system networks were originated and guaranteed by itself. It can be a security by obscurity. Recently, most of devices in the control systems are changing with communication capability, and the interoperability between devices is very significant. Thus, effective management system for control system networks have been required and this have triggered connection between the control system network and external system networks. These changes make control system management easier than before, but the threat of cyberattacks from external networks are also increasing. To prevent a variety of security attacks, many security standards and solutions are applied to control systems. In this paper, we present scenario-based attack and propose a countermeasure using security control of field devices in order to improve security in control system networks.

Driven by recent telecommunication demand, shared communication channels are more abundant today than ever before. These shared wired/wireless networks for communication are being exploited more and more in control systems to connect sensors, controllers and actuators resulting in so-called networked control systems (NCSs). NCSs replace the more traditional control systems where dedicated point-to-point (wired) connections are being used. The advantages of using NCS technology are inexpensive and easily modifiable communication links which allow control algorithms to be easily implemented in situations where dedicated connections are not possible (either economically or physically). However, the drawback is that the control system is susceptible to undesirable (possibly destabilizing) side-effects such as time-varying transmission intervals, time-varying delays, packet dropouts, quantization and a shared communication medium. These network-induced effects undermine fundamental assumptions on which traditional control theory is built and, therefore, it is essential to develop new techniques and tools that can be used to analyze and/or design control systems which communicate via a shared network. This thesis advances NCS analysis and design methodologies by contributing new theoretical developments, new software tools and new experimental validation results. The first new theoretical development is in the area of analyzing robust stability properties with respect to network-induced effects. A sum of squares (SOS) approach for a class of nonlinear NCSs incorporating bounded time-varying delays, bounded time-varying transmission intervals and a shared communication medium is developed. Mathematical models that describe these nonlinear NCSs are cast into suitable hybrid system formulations. Based on these hybrid system formulations, (families of) Lyapunov functions are constructed using SOS techniques. Amongst other benefits, it is shown that this technique improves the guaranteed robustness margins compared to existing work. The second new theoretical development concerns the design of networkaware decentralized controllers guaranteeing robust stability properties with respect to network-induced effects. We develop one of the first approaches based on semidefinite programming techniques to synthesize stabilizing decentralized observer-based output-feedback controllers for linear plants where the controllers, sensors and actuators are connected via a shared communication network subject to time-varying transmission intervals and delays. To effectively deal with the shared communication medium, a switched observer structure is adopted that switches based on the transmitted measured outputs and a switched controller structure is also adopted that switches based on the transmitted control inputs at each transmission time. By taking a discrete-time switched linear system perspective on modeling these decentralized NCSs, we are able to derive a general model that captures all these networked and decentralized control aspects. We provide linear matrix inequality (LMI)-based synthesis conditions which, if satisfied, provide stabilizing observer-based controllers that are both decentralized and robust to network effects. Regarding new software tools, the first prototype of a toolbox is developed to automate (robust) stability analysis (and controller design) for NCSs. Specifically, it is shown that the toolbox can be employed to efficiently verify if a linear time-invariant (LTI) plant and an LTI controller interconnected with a shared network are robust to certain network imperfections. The main intention of the toolbox is to make the available theory readily accessible to and applicable for the general control community. Additionally, the chosen software structure enables the incorporation of custom models or custom stability/performance analysis conditions in an easy manner, thereby allowing the control community to contribute and to further develop the toolbox. Finally, an experimental case study involving a wirelessly controlled inverted pendulum/cart system is investigated. In particular, the communication network itself is analyzed such that the network-induced effects can be characterized in terms of bounds on the transmission intervals and transmission delays. Based on these bounds, the prototype toolbox is applied to analyze the robustness regions for different performance specifications, which aid in tuning the controller to achieve more closed-loop robustness with respect to the network-induced effects. This leads to a validation of the developed theory in an experimental setting. In addition to the validation of the developed theory, many new insights into the network behavior are obtained and explained, thereby raising new interesting questions for future research on NCSs.

This paper introduced the concept, the classification and the control principal of network behaviors,discussed the concept, composition and structure, and the behavior control of the controlled network system, then proposed the detection and control model of abnormal behavior in controlled network system. This model of abnormal behavior detection was designed by combining misuse and intrusion detection mechanism, and is the specific application of the research on network behavior and controlled theory, and it controls the network behaviors especially abnormal behaviors. The theory is the basis for establishing the dynamic controllable network security system. With the development of network and information technologies, it seems that the network size, the diversity of network equipment and the complexity of network topology structure are constantlyincreasing, which leads to the probability of security problems emergeis also increasing. However, the traditional network security measures cannot meet the needs of the actual complex network activities, the existing information network has an urgent need to propose a new theory or new method which can reflect the overall network security and behavior control states. As a kind of efficient, scientific and reasonable network security theory, the controlled network is the integration of existing network security technologies and measures, and the aim of it is to construct a controlled network and solve the network security problems(1).

Networked control systems (NCSs) have, in recent years, brought many innovative impacts to control systems. However, great challenges are also met due to the network-induced imperfections. Such network-induced imperfections are handled as various constraints, which should appropriately be considered in the analysis and design of NCSs. In this paper, the main methodologies suggested in the literature to cope with typical network-induced constraints, namely time delays, packet losses and disorder, time-varying transmission intervals, competition of multiple nodes accessing networks, and data quantization are surveyed; the constraints suggested in the literature on the first two types of constraints are updated in different categorizing ways; and those on the latter three types of constraints are extended.

ABSTRACT: Many companies today utilize interactive data visualization to present accounting information to external users on their investor relations websites and to internal users in applications such as enterprise resource planning, Balanced Scorecard, network security, and fraud detection systems. We develop a taxonomy for examining the current state of interactive data visualization research related to accounting decision making. We organize our review around three themes: the relationship between task characteristics and interactive data visualization techniques, the relationship between decision maker characteristics and interactive data visualization techniques, and the impact of interactive data visualization techniques on decision processes and outcomes. The review categorizes relevant research, describes the research questions addressed, and suggests avenues for further research.

The rapid growth in the size and complexity of modern Cyber-Physical Systems (CPS) imposes increasing demand for the embedded resources, especially the communication resources. As a result, resource-efficient CPS design has become an important issue. Towards the design of networked embedded control systems, a major branch of CPS, reliable and deterministic communication is able to achieve satisfactory control performance. However, the amount of this type of resource that can be provided by the embedded platform is often limited. On the other hand, it is difficult to guarantee the control performance with non-deterministic communication resources, due to their unpredictable behavior. In this paper, we propose a novel control scheme to efficiently utilize elastic communication resources. In general, the non-deterministic communication resources are flexibly deployed on top of the deterministic communication resources to achieve stability and good control performance. In the rare worst-case, when non-deterministic communication is completely unavailable, the deterministic communication resources are used to guarantee stability and the control performance satisfying the design requirement. The experimental results show that the performance of the control application is ensured to satisfy the design requirement in the worst case and that better control performance is achieved when non-deterministic resources are available.

At present, control system security efforts are primarily technical and reactive in nature. What has been overlooked is the need for proactive efforts, focused on the IT security research community from which new threats might emerge. Evaluating cutting edge IT security research and how it is evolving can provide defenders with valuable information regarding what new threats and tools they can anticipate in the future. Only known attack methodologies can be blocked, and there is a gap between what is known to the general security community and what is being done by cutting edge researchers --both those trying to protect systems and those trying to compromise them. The best security researchers communicate with others in their field; they know what cutting edge research is being done; what software can be penetrated via this research; and what new attack techniques and methodologies are being circulated in the black hat community. Standardization of control system applications, operating systems, and networking protocols is occurring at a rapid rate, following a path similar to the standardization of modern IT networks. Many attack methodologies used on IT systems can be ported over to the control system environment with little difficulty. It is extremely important to take advantage of the lag time between new research, its use on traditional IT networks, and the time it takes to port the research over for use on a control system network. Analyzing nascent trends in IT security and determining their applicability to control system networks provides significant information regarding defense mechanisms needed to secure critical infrastructure more effectively. This work provides the critical infrastructure community with a better understanding of how new attacks might be launched, what layers of defense will be needed to deter them, how the attacks could be detected, and how their impact could be limited.

Network control system (NCS) is a kind of distributed control system, which is widely used in industrial control process. The communication network is used to exchange information and control signals among various physical components of subsystems. The transmission of data and information on the communication network to achieve system control will lead to the inevitable delay of information transmission time, which will reduce the performance and even make the system unstable. Reducing network traffic is one of the most effective methods to reduce the impact of network control system delay on system performance. This paper discusses the adjustable deadband as a method to reduce network traffic in networked control systems, and proposes a modeling method of networked control systems with random delay and communication constraints based on quasi T-S fuzzy model. Based on robust fault-tolerant control theory and information scheduling theory, the integrity design of this kind of networked control system is analyzed. After detailed theoretical analysis, simulation results are given to further verify the proposed scheme.

This paper designs a kind of distributed network control system based on ZigBee wireless communication technology. Firstly, a summary of device type and topology structure in ZigBee network is given. Then, hardware circuit design of the controller in this system is also provided. Furthermore, this paper discusses a communication model of control system, ZigBee organizing network technology and establishment process of system communication in detail. Finally, an application example of distributed control system based on ZigBee network is proposed.