Decentralized Access Control for IoT Data Using Blockchain and Trusted Oracles

The Internet of Things (IoT) is a network of connected electromechanical devices that have limited computational, networking, and storage capabilities. IoT is now widely used in healthcare, smart cars, smart grids, smart homes, smart manufacturing, and smart cities. IoT devices sense, monitor, and collect data where it can be shared with legitimate users. IoT data can be aggregated, stored and made available by multiple IoT data hosting providers. IoT data storage, management, and access involve multiple stakeholders that many include admins, owners of IoT devices, data repository hosts and providers, normal users, etc. Decentralized control and trusted management of such IoT data become critical, in which the management and access control of data is not centralized, i.e., under the control of a single entity. To date, the available methods for for access control in IoT systems are mainly centralized. In this paper, we propose a decentralized access control system for IoT data using blockchain and trusted oracles. We use features of blockchain and smart contracts to propose a decentralized, scalable, and secure management solution for accessing IoT data. In addition, we use oracles as gateways that interface with the blockchain, IoT data hosts, and remote users to provide decentralized, trusted, and uniform source feeds for IoT data. The paper also presents architectural design, interactions, logic flow, algorithms, implementation details, along with cost, computation, and security evaluation. The full code of the developed smart contracts is made publicly available at GitHub.