FACT: A Flexible Access Control Technique for Very Large Scale Public IoT Services

With the advances in sensing, networking, control-ling, and computing technologies, more and more IoT (Internet of Things) devices are emerging. They are envisioned to become part of public infrastructure in the near future. In face of the potentially large-scale deployment of smart devices in public venues, public IoT services impose new challenges on existing access control mechanisms especially in terms of efficiency. In this work, we design a flexible access control management technique which not only provides automatic and fine-grained access control management, but also incurs low overhead in large scale settings, making it suitable for product deployment. The flexible access control technique is comprised of a highly efficient dual-hierarchy access control structure and associated information retrieval algorithms. Using this technique, we develop a large-scale IoT device access control mechanism named FACT to overcome the efficiency problems in granting and inquiring access control status over millions of devices in distributed environments. Our mechanism also offers a convenient pay-and-consume scheme and plug-and-play device management for easy adoption by service providers. We have conducted extensive experiments, and the results have demonstrated the practicality, effectiveness, and efficiency of our flexible access control technique.