A Blockchain-Based Mutual Authentication Protocol for Smart Home.

Smart home is an emerging paradigm that facilitates the user to control remotely appliances and devices from anywhere through the internet connection using a networked device. The privacy-preserving authentication protocol is an important way for the security and privacy of remote access in the smart home. Recently, Lin et al. proposed a blockchain-based mutual authentication (HomeChain) protocol to achieve reliable auditing and anonymous authentication. Their work has drawn wide attention and continues to be widely cited. However, we propose two universal attacks against HomeChain and demonstrate that in Homechain, a malicious home gateway can break the anonymity of users and a malicious authorized user can break the traceability. Meanwhile, to address the above problems, we design a new secure and privacy-preserving blockchain-based authentication protocol by leveraging a secure short group signature scheme. Finally, we conduct extensive experiments and compare our performance with that of HomeChain. The experiment results show that our protocol achieves stronger security and privacy at the expense of a slightly higher computation and communication cost.