An ECC- and OT-based privacy-preserving authentication scheme for smart home systems

Although the integration of 5G and AIoT technologies has created new opportunities for smart home systems, security issues remain a major barrier to their sustainable development and widespread adoption. Traditional identity authentication methods in smart home systems suffer from high computational complexity, complicated key management, and poor scalability, making them unsuitable for smart home environments with stringent storage and energy constraints. In addition, users’ private data face serious threats during the processes of collection, transmission, and storage. To address these challenges, this paper proposes a lightweight identity authentication and key agreement scheme integrating Oblivious Transfer (OT) and Elliptic Curve Cryptography (ECC). The proposed scheme adopts multi-factor authentication based on fingerprints, passwords, and hardware identifiers to enable mutual authentication, while timestamps, counters, and dynamic identity updates are employed to resist replay attacks and ensure forward secrecy and user privacy. Comprehensive security analysis and performance evaluation demonstrate that the proposed scheme reduces storage overhead by 19.49%–78.70%, communication overhead by 8.85%–62.61%, and computational cost by 0.01%–90.04%, thereby providing a secure and efficient authentication solution for resource-constrained smart home environments.