Abstract:

According to the features of intrusion tolerant system compared to ordinary network system, an evaluating the security situation special for intrusion tolerantsystem is proposed. Three evaluation indexes are included: firstly, the confidentiality of data, the integrality of data and the usability of service are proposed based on the influence of intrusion and the function of intrusion tolerance. Secondly, the ways of quantifying the indexes are given according to the features of each index, and thirdly, the security situation of intrusion tolerant system is evaluated dynamically through computing the three evaluation indexes. Experiment shows that the method is easy to be operated, and reflects the actual security status of intrusion tolerant system. 

Key words: intrusion tolerance, security, situation evaluation, evaluation index, network security