Fog-enabled private blockchain-based identity authentication scheme for smart home

As the Internet of Things (IoT) technology continues to advance, it has found widespread application in various fields, including smart health, smart cities, and smart transportation. Among these applications, smart homes are particularly noteworthy due to their intimate connection to our daily lives. However, the use of smart devices in a home environment exposes users to various security threats, such as impersonation attacks and insider privilege attacks, as users must communicate with multiple devices through a public channel. Additionally, traditional authentication schemes that rely on trusted third-party present a single point of failure, as users and smart devices must be registered and authenticated by a central authority. Blockchain technology offers a decentralized, tamper-proof, and flexible solution for authentication and access control of data. By using blockchain, the single point of failure problem in traditional authentication schemes can be resolved. In the context of smart homes, the real-time nature of the environment necessitates the use of fog nodes to provide localized computing services. Fog nodes are closer to IoT devices than cloud nodes, making fog computing more efficient and faster than cloud computing. This paper proposes an authentication scheme for blockchain-enabled fog nodes in smart homes. The scheme involves registering all fog nodes and intelligent devices on a local private blockchain, and authentication is performed jointly by smart contracts on the blockchain and off-chain operations. The scheme provides comprehensive security and better performance, as demonstrated by security analysis and performance evaluation. Moreover, the proposed scheme offers a certain level of user privacy protection.