Network Intrusion Detection by a Multi-stage Classification System

A serial multi-stage classification system for facing the problem of intrusion detection in computer networks is proposed. The whole decision process is organized into successive stages, each one using a set of features tailored for recognizing a specific attack category. All the stages employ suitable criteria for estimating the reliability of the performed classification, so that, in case of uncertainty, information related to a possible attack are only logged for further processing, without raising an alert for the system manager. This permits to reduce the number of false alarms. The proposed multi-stage intrusion detection system has been tested on two different services (http and ftp) of a standard database used for benchmarking intrusion detection systems. The experimental analysis highlights the effectiveness of the approach: the proposed system behaves significantly better than other multi-expert systems performing classification in a single stage