MQTT-based Internet of Things networks face major security problems because they have high-dimensional data, class imbalance, and no detection mechanisms that can be understood. This paper proposes a unified intrusion detection framework that integrates attention-based deep learning, GAN-driven data augmentation, and MDA-based feature selection (CNN-LSTM-Attention). The proposed pipeline outperforms both classical and recent state-of-the-art baselines. When tested on MQTTEEB-D, a real-world MQTT dataset with 200,000 flows, an accuracy of 99.12% and macro F1-score of 98.37 were achieved. However, the attention maps provide clear explanations for the obtained prediction, and the system performs well even against tough attacks such as SlowITe: 96–98%. Moreover, the system's very short inference time makes it possible to deploy on a real IoT gateway with limited resources. The synergistic combination of feature engineering, generative augmentation, and interpretable deep learning sets a standard for reliable and effective IoT/MQTT intrusion detection.
link
https://doi.org/10.54216/JCIM.180101