A Hybrid Model for Network Security Systems: Integrating Intrusion Detection System with Survivability

Computer networks are now necessities of modern organisations and network security has become a major concern for them. In this paper we have proposed a holistic approach to network security with a hybrid model that includes an Intrusion Detection System (IDS) to detect network attacks and a survivability model to assess the impacts of undetected attacks. A neural network-based IDS has been proposed, where the learning mechanism for the neural network is evolved using genetic algorithm. Then the case where an attack evades the IDS and takes the system into a compromised state is discussed. We propose a stochastic model which enables us to do a cost/benefit analysis for systems security. This integrated approach allows systems managers to make more informed decisions regarding both intrusion detection and system protection.