Fast Model Update for IoT Traffic Anomaly Detection With Machine Unlearning

It is often needed to update deep learning-based detection models in traffic anomaly detection systems for the Internet of Things (IoT) because of mislabeled samples or device firmware upgrades. Machine unlearning, a technique that quickly updates the anomaly detection model without retraining the model from scratch, has recently attracted much research attention. We propose a novel machine unlearning method, called virtual federated learning approach (ViFLa), which groups training data based on estimated unlearning probability and treats each group as a virtual client in the federated learning framework. Since the virtual clients are physically in the same machine, ViFLa only leverages the concept of data/local models isolation in federated learning without incurring any network communication. ViFLa adopts an attention-based aggregation method called enhanced class distribution weighted sum (ECDWS) to tackle the nonindependent and identically distributed (non-iid) data problem caused by the data grouping strategy. It also introduces a new state transition ring mechanism into the statistical query (SQ) learning framework to update the local model of each virtual client quickly. Using real-world IoT traffic data, we showcase the benefit of ViFLa regarding its efficiency and completeness for model updates in the context of IoT traffic anomaly detection.