A Cross-Dataset based Zero-Day Intrusion Detection System by Integrating Siamese Network and Reinforcement Learning
Zero-day threats are nascent for the Internet of Things (IoT) network security, which demands cognitive detec-tion mechanisms that can identify emerging malicious behavior. Conventional intrusion detection mechanisms fail to generalize dynamic zero-day exploits within sophisticated IoT environments. This paper proposes a hybrid zero-day intrusion detection system using Siamese network-based anomaly correlation and reinforcement learning-based adaptive defense. Furthermore, the paper uses unsupervised machine learning classifiers over benchmark IoT datasets with the intention of detection of known attack types compared to unknown anomalies using distance-based similarity analysis to detect possible zero-day attacks. To facilitate adaptability, a Proximal Policy Optimization (PPO) reinforcement learning-based agent dynamically adjusts the defense policy with continuous feedback and optimization. Experimental evaluations demonstrate 99.28% training accuracy, 99.07% accuracy in unknown attack detection, and 93.94% zero-day detection ratio, confirming the convergence and stability of the model on datasets.The system offers a self-learning and extensible defense mechanism of IoT deployments by finding the right balance between precision, latency and false positives. This deep anomaly correlation with adaptive reinforcement learning is a firm base on which the next generation and autonomic cyber security solutions can take the reins as the zero-day threats keep changing their course.