Design of a Decentralized Identifier-Based Authentication and Access Control Model for Smart Homes

In recent years, smart homes have garnered extensive attention as a prominent application scenario of IoT technology. However, the unique characteristics of smart homes have brought forth serious security threats, emphasizing the paramount importance of identity authentication and access control. The conventional centralized approach is plagued by the issue of having a "single point of failure," while existing distributed solutions are constrained by limited device resources and the complexities of identity authentication. To tackle these challenges, this paper proposes a smart home authentication and access control model based on decentralized identifiers (DIDs). By leveraging the inherent decentralization of DIDs, which rely on blockchain, a distributed environment is constructed, effectively mitigating the problem of the "single point of failure." In this model, every participant in the smart home system, including users and smart devices, is uniquely identified by DIDs and through the integration of an improved capability-based access control scheme, which streamlines the user identity authentication process, reduces authentication complexity, and enables convenient cross-household access with a single registration. Our experimental results demonstrate that the application of decentralized identifiers provides the model with various security attributes, including confidentiality, integrity, and traceability. Additionally, the model exhibits low time costs for each module, ensuring timely responses to access service requests and incurring lower gas consumption compared to other Ethereum-based methods. Thus, our research proposes a lightweight authentication and access control solution suitable for smart home environments.