Research For The Method Of Quantitative Analysis For The Intrusion Tolerant Systems Dynamic Security

As a third generation safe system, an intrusion tolerance system is facing more and more attention. With the breakthrough of the intrusion tolerance technology, more tolerance systems are coming into being, and intrusion tolerance techniques become mature. But how to identify an effective one from an ineffective one is a more complicated task and topic, further more, because of the complex structure, it makes tough to analyze the system's safety in quantity or evaluate them accurately, needless to mention a generally accepted standard or method to be used.Analyzing the safety of an intrusion tolerance system is to analyze the capacity of defending and tolerating offensive behaviors. The current analyzing methods in quantity don't take the environment factors into the account. To assess the safety of different intrusion tolerant systems, to make the would-be design of framework of intrusion tolerance systems better, more attention should be put in the overall evaluation of dynamic safety, that is, a more dependable and practical way of evaluation of the system safety is needed urgently.The thesis presents a safe quantity way to expose the windows to make the system work better. The exposing windows can reflect the procedure of the changes of systems dynamically, the parameter is used in the process of analyzing Markov process, and thus the changes of the system's safety will be reflected objectively. This research achieves a more realistic quantitative result which involved in the exposing windows, the intrusion residence time, and the analyzing in quantity by the decision tree. The quantitative analysis method is vivificated by the analog result, and it offers a theoretical basis for a safer tolerance system.