Optimizing Security Measures in an Intrusion Tolerant Database System

摘要

In this paper we describe the stochastic behavior of an intrusion tolerant database (ITDB) system and quantitatively evaluate its security measures. More specifically, we develop a semi-Markov model and derive three security measures; system availability, system integrity and rewarding availability. By introducing an additional control parameter called the switching time, we develop secure control schemes of the ITDB, which maximize the respective security measures, and show numerically that the security measures can be improved by controlling the switching time.