Modeling and Evaluation of Intrusion Tolerant Systems Based on Dynamic Diversity Backups

Based on the technology of dynamic diversity backups, an intrusion tolerant system is proposed which guarantees the performance of the system and does not degrade drastically when it is exposed to outside attacks. By analyzing the consequence of the attacks, we give the attack model and model of the proposed intrusion tolerant system by General Stochastic Petri Net (GSPN). Through it, we can evaluate the efficiency of the intrusion tolerant system (ITS) based on the dynamic diversity backups. In the end of the paper, we analyze the proposed system with three diversity backups and random schedule strategy among the backups by the tool SPNP (Stochastic Petri Net package). The results show that the ITS is affected lightly under the heave attacks, which implies that the system can defend most intrusion effectively.