Security and Privacy Challenges in Next-Generation IoT Systems: A Review of Threats and Mitigation Techniques

The Internet of Things (IoT) has quickly developed into a force that is revolutionizing several industries, enabling seamless interconnection and autonomous communication among smart devices. Artificial intelligence (AI), edge/fog computing, blockchain, as well as 5G/6G communication networks are some of the cutting-edge technologies that are combining to create next-generation IoT systems. The effectiveness, scalability, and intelligence of IoT networks have been greatly increased by these developments, enabling real-time data analytics as well as decision-making. This study offers a thorough examination of the architecture, key enabling technologies, and security mechanisms shaping next-generation IoT. It also looks at the integration of intelligent systems for adaptive control and highlights prominent use cases in domains like Autonomous transportation, smart healthcare, as well as industrial automation. In addition, the paper outlines the evolving role of data-driven architectures and decentralized frameworks in creating more autonomous and self-healing IoT systems. By synthesizing current trends and technological advancements, this paper provides academics and practitioners with a fundamental resource for creating resilient and future-ready IoT ecosystems.