BacS: A blockchain-based access control scheme in distributed internet of things

Distributed Internet of Things (Distributed IoT) is a large-scale, heterogeneous, dynamic distributed architecture environment which is gradually formed based on Internet of Things (IoT) technology. In order to cope with the large number access requirements for IoT data brought by application expansion, the data of IoT devices are usually stored in the management server (DMS) of current domain, and adopt a centralized access control mechanism to user. This centrally approach can easily cause data to be tampered with and leaked. Moreover, registering different identities when user accesses different domains increases the difficulty to manage his identities. Therefore, this paper proposes a blockchain-based access control scheme called BacS for Distributed IoT. In BacS, firstly, we use account address of the node in blockchain as the identity to access DMS, redefine the access control permission of data of devices and store on blockchain. Then we design processes of authorization, authorization revocation, access control and audit in BacS. Finally, we use a lightweight symmetric encryption algorithm (SEA) to achieve privacy-preserving for Distributed IoT system. We build a credible experimental model on Ethereum private chain, results show that BacS is feasible and effective that it can achieve secure access in Distributed IoT environment while protecting privacy.