Network Intrusion Detection using a combination of artificial neural networks in a hierarchical manner

With the growth of information technology, network security is one of the major issues and a great challenge. Intrusion detection systems, are the main component of a secure network that detect the attacks which are not detected by firewalls. These systems have a huge load of data to analyze. Investigations show that many features are unhelpful or ineffective, so removing some of these redundant features from the feature set is a solution to reduce the amount of data and thus increase the speed of the detection system.  To improve the performance of the intrusion detection system it is essential to understand the optimal property set for all kinds of attacks. This research, in addition to presenting a method for intrusion detection based on combining neural networks, also introduces a method for extracting optimal features of the KDD CUP 99 dataset which is a standard dataset for testing computer networks intrusion detection methods.