A hybrid CNN-transformer with explainable AI for robust IoT and IIoT intrusion detection


Saleh R. A. A., Alwadain A., Saif M. A. M.

International Journal of Machine Learning and Cybernetics, cilt.17, sa.5, 2026 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 17 Sayı: 5
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1007/s13042-026-03055-y
  • Dergi Adı: International Journal of Machine Learning and Cybernetics
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC
  • Anahtar Kelimeler: CNN-transformer, Cyber threat detection, Deep learning, Explainable artificial intelligence (XAI), IIoT, Intrusion detection system (IDS), IoT security
  • Kocaeli Üniversitesi Adresli: Evet

Özet

The rapid expansion of IoT and IIoT networks has introduced unprecedented cybersecurity challenges, with traditional Intrusion Detection Systems (IDS) struggling to detect evolving cyber threats. Existing deep learning-based IDS often fail to capture both local spatial features and long-range dependencies in network traffic, resulting in suboptimal threat detection. To bridge this research gap, this study proposes a hybrid CNN-Transformer model that leverages the complementary strengths of both architectures. The Convolutional Neural Network (CNN) component excels at extracting localized feature patterns from sequential data, while the Transformer’s self-attention mechanism models the global, long-range dependencies between these patterns. The proposed model was rigorously evaluated on the Edge-IIoTset dataset and benchmarked against standalone CNN-only, Transformer-only, and Deep Neural Network (DNN) models. Experimental results demonstrate that the CNN-Transformer model achieves superior performance, attaining the highest weighted F1-score of 0.82 and exceptional Area Under the Curve (AUC) scores, including perfect 1.000 AUCs for critical attack classes like DDoS-ICMP, DDoS-UDP, and MITM. This result represents a more robust classification profile than the standalone CNN (F1: 0.82) and significantly outperforms the Transformer-only (F1: 0.81) and DNN (F1: 0.75) models. Additionally, Explainable AI (XAI) techniques were incorporated to enhance transparency, identifying critical features as key indicators for specific attack types. This research provides a robust, high-accuracy IDS framework for next-generation IoT cybersecurity, paving the way for more intelligent and adaptive threat detection systems.