A Lightweight Intrusion Detection System for Constrained IoT Devices
Traditional Internet of Things (IoT) security solutions often rely on heavy cloud-based or gateway-class infrastructure, which is frequently unsuitable for resource-limited hardware due to latency, power, and memory constraints. This paper proposed a resource-aware behavioral Intrusion Detection System (IDS) designed for highly constrained IoT devices. To address these challenges, the proposed system implements real-time application-layer monitoring on an ESP32 Microcontroller Unit (MCU) and utilizes an offline-trained logistic regression model for autonomous, on-device inference. The detection mechanism extracts behavioral features, such as request rates, failed authentication attempts, and invalid resource access within sliding time windows to estimate attack probabilities. Experimental evaluations under controlled scenarios involving flood, brute force, and scan attacks demonstrate that the system achieves high accuracy, precision, and recall. These findings indicate that effective cyber intrusion detection and local mitigation can be successfully executed directly on a single MCU while preserving stable runtime performance and minimal memory usage. Finally, this paper highlights the need for further optimizations to improve robustness and scalability.