As the Internet of Vehicles (IoV) rapidly gains popularity, the Controller Area Network (CAN) faces increasingly severe security threats. Most of the existing research on protecting the CAN bus has been based on artificial intelligence models, which require complex feature extraction and training processes and are too resource-intensive for deployment in resource-constrained CAN environments. To address these challenges, we propose a lightweight intrusion detection system based on locality-sensitive hashing that achieves efficient security protection without relying on complex machine learning and deep learning frameworks. We employ the Nilsimsa algorithm to compute hash digests of the data, using the similarity scores of these digests as anomaly scores to identify abnormal traffic. Evaluations show that our method achieves an accuracy of 98%, and tests of the system’s overhead confirm its suitability for deployment in resource-limited CAN scenarios.

Out-of-distribution (OOD) detection is critical for securing Internet of Things (IoT) systems, particularly in applications such as intrusion detection and device identification. However, conventional classification-based approaches struggle in IoT environments due to challenges like large class numbers and data imbalance. To address these limitations, we propose a novel framework that combines class mean clustering and a group-level feature distance loss to optimize both intra-group compactness and inter-group separability. Our framework utilizes Mahalanobis distance for robust OOD scoring and Kernel density estimation (KDE) for adaptive threshold selection, enabling precise boundary estimation under varying data distributions. Experimental results on real-world IoT datasets show that our framework outperforms baseline techniques, achieving at least a 10% improvement in AUROC and a 33% reduction in FPR95, demonstrating its scalability and effectiveness in complex, imbalanced IoT scenarios.