Sequential Binary Classification for Intrusion Detection

Network Intrusion Detection Systems (IDS) have become increasingly important as networks become more vulnerable to new and sophisticated attacks. Machine Learning (ML)-based IDS are increasingly seen as the most effective approach to handle this issue. However, IDS datasets suffer from high class imbalance, which impacts the performance of standard ML models. Different from existing data-driven techniques to handling class imbalance, this paper explores an approach based on the structure of the classifier model, to handling class imbalance in multi-class classification (MCC) problems. The proposed approach - Sequential Binary Classification (SBC), is a hierarchical cascade of (regular) binary classifiers. Experiments on benchmark IDS datasets demonstrate that the structural approach to handling class imbalance, as exemplified by SBC, is a viable approach to handling the issue.