Research On Key Technologies Of Effectiveness Evaluation For Security System

The security yearned by the Chinese ancients is that if aught was dropped upon the road, none picked it up, nor were the doors of houses locked at night. Our government also outlines a beautiful blueprint for people’s life in the future, which is the construction of a harmonious society and the building of safe cities. What is "security"? Everyone have their own definitions. I think the best security is to ensure the safety of anybody or anything in everywhere all the time. The best security is called "Big Security", which is beneficial to the whole society and the public. How to realize "Big Security"? The answer is the construction of big security networks, which need the participation of governments, the society and the public."Big Security Networks" uses a variety of protection measures, which include civil defense, physical defense and technology defense, and preventive measures, which is include detection, response and delay, to provide the multi-level and multi-dimensional comprehensive protection. With the constant development and maturity of Cloud Computing and Internet of Things, security systems are developing towards security networks. At present, there are some research results on the performance assessment and risk assessment of security systems. But they are mostly aimed at regarding security systems as some separate systems. The related research results don’t fit security networks. So it is urgently necessary to establish a scientific and objective method of performance evaluation and risk assessment for security networks according to their characteristics to instruct the construction of security networks.To address the above problems, this dissertation is funded by the National Natural Science Foundation of China Project "Research on Social Security System Risk and Effectiveness Evaluation Based on Risk Entropy Model"(No.61170023), project of central colleges of special funds basic research and operating expenses)-Young Teacher Grant "The Effectiveness Evaluation on Security System Based on Risk Entropy Model"(No.3101014) and doctorial independent research projects of Wuhan University "Research on Risk Assessment Technology of Social Safety Protection System Based on Risk Entropy Model"(No.20102110101000117) to carry out the research on Performance Evaluation and Risk Assessment of Security Networks. In this dissertation, a security system is regarded abstractly as a network, which is made up of security nodes and the paths between security nodes. From the point of view of network, we study the effectiveness evaluation of a security node or a security system. Firstly, we construct the failure evaluation model of a security device to measure or predict the failure probability of a security equipment at any time through the statistical analysis of failure characteristics data. Secondly, we propose protection failure evaluation model to analyze the protection failure probability of a security node according to failure probability of security equipment. Thirdly, on the basis of the risk entropy model and protection failure model, we construct the effectiveness evaluation model of a security node. Finally, a security system is regarded abstractly as a network, which is made up of security nodes and the paths among security nodes. On the basis of the reliability theory, we construct the effectiveness assessment model of a security system based on reliability analysis and use the reliability of the most vulnerable path of a security network to measure its effectiveness. The specific research works are as follows:(1)Research on Failure Assessment of a Security Equipment Based on the Analysis of failure characteristics The definition of failure assessment is to measure the failure probability of security equipment under the stated conditions for a given period of time. According to the mathematical statistics theory, we construct the security equipment failure characteristic statistical model to evaluate the failure probability of security equipment at any time through the failure assessment index.(2)Research on Protection Failure Assessment of Protection Abilities Based on Failure Probability of Security EquipmentProtection effectiveness depends not only on protection abilities but also on the failure probability of protection abilities. The current security system effectiveness evaluation research neglect the factor of protection ability failure and this will affect the science and rationality of the effectiveness evaluation results. The failure of protection and security equipment has a close relationship. So we abstractly regard a kind of protection capability as a network, which is made up of security devices and propose protection failure evaluation model to analyze protection failure probability.(3)Research on Effectiveness Evaluation of Security Node Based on Risk Entropy and Failure ModelWe use the risk entropy model to evaluate the effectiveness of protection capabilities of a security node through the construction of the effectiveness evaluation index. Then we abstractly regard a protection capability as a network, which is made up of security devices and the paths among security devices. The failure probability of a kind of protection capability can be calculated by the protection failure evaluation model. Finally, the effectiveness evaluation model of security node is established on the basis of protection capability failure model and risk entropy. The model can be used to assess the effectiveness of a security node at any time, reflect the change trend of effectiveness over time and make the effectiveness evaluation results more scientific.(4)Research on Effectiveness Assessment of Security System Based on the Most Vulnerable PathA security system is regarded abstractly as a network, which is made up of security nodes and the paths among security nodes. We introduce the concept of path cost and set up the path cost calculation model on the basis of the effectiveness of security nodes. Finally we construct the effectiveness assessment of security system according to the reliability theory to evaluate the effectiveness of a security system with the reliability of the most vulnerable paths between the entrances and protected assets. The research results can be used to resolve the problem of effectiveness assessment on complex security system.We study the effectiveness assessment of security system from key evaluation technologies, evaluation methods and basic evaluation theories in this dissertation. The models and methods proposed in this paper can be used to resolve the problem of effectiveness assessment on complex security system. The related research results provide important scientific significance and application promotion to the construction of a scientific, effective and efficient security system. At the end of this dissertation, we summarize the research achievement and look into the research work in the future.