TACL: Trust-Based and Scalable Access Control for IoT Using Blockchain

Internet of Things (IoT) security, privacy and trust remain the major challenges, mainly due to the massive scale and distributed nature of IoT networks. Access control systems are used in security to control access to valuable resources. This paper proposes a novel trust-based access control (TACL) model for IoT. Trust provides IoT devices with a natural mechanism to judge other devices, similarly to how we tackle security in our human society. Trust relationship among IoT devices provides a means to influence the future behaviours of their communication. Services and resources should be shared with a requesting device only if other devices trust that device. An access control system equipped with a trust management allows the computation of trust to make efficient decision in controlling access to resources. TACL is an advanced access control system that takes trust information into consideration before allowing subjects to perform operations on resources. The EOS blockchain is used as a tool to publish and evaluate the performance of the proposed model. The results demonstrate that TACL is a lightweight and scalable protocol designed to achieve fine-grained access control.