Blockchain and structural relationship based access control for IoT: A smart city use case

Smart city is one of the major Internet of Things (IoT) applications and has become an emerging paradigm with the recent advancements of IoT devices and sensors. But the heterogenous nature of a smart city IoT environment makes it vulnerable to many privacy and security concerns and introduces significant challenges for access control of IoT resources especially where access needs to be provided to third parties and external organizations. This paper proposes a new structural relationships-based access control (SRBAC) model that can be used to delegate resource access rights to users in a large scale IoT scenario like smart city while keeping the resource owner in full control. The proposed architecture uses smart contracts and public blockchain for managing access control for external users and a local off-block chain storage for managing access control for organization’s internal users and enforcing fine-grained access control for the resources.