Hybrid Privacy-Preserving Access Control Mechanism Using Blockchain and Attribute-Based Access Control for Smart Home

The rise of the Internet of Things (IoT) devices in smart homes has raised concerns about privacy breaches and unauthorized access to sensitive data. However, traditional access control mechanisms often fail to address these issues that infringes on the privacy of the users of this technology. This study proposes a privacy-preserving access control mechanism which uses blockchain technology and attribute-based access control to authenticate users, authorize access to smart home devices, and regulate data access while preserving user privacy. Thereby, authentication users using attributes like biometric data or passwords while avoiding direct disclosure of personal information. Access requests are processed using predefined policies stored in smart contracts on the blockchain, with short-lived tokens used to mitigate risks like replay attacks and user profiling. The mechanism uses the Go-Ethereum blockchain runtime framework and the Solidity smart contract development language on an edge server, with smart contracts managed using the Remix Integrated Development Environment (IDE). Data encryption and user authentication are ensured through the Advanced Encryption Standard (AES) and the mechanism effectively mitigates potential threats like Denial-Of-Service (DOS) attacks and modification attacks. Future research should enhance scalability, optimize resource utilization, and integrate emerging technologies like differential privacy.