A Lightweight Key Agreement Protocol Based on Chinese Remainder Theorem and ECDH for Smart Homes

Security and efficiency are the two main challenges for designing a smart home system. In this paper, by incorporating Chinese remainder theorem (CRT) into the elliptic curve Diffie–Hellman (ECDH), a lightweight key agreement protocol for smart home systems is constructed. Firstly, one-way hash authentication is used to identify the sensor nodes instead of mutual authentication to reduce the authentication cost. Secondly, the CRT is introduced to enhance the security of the original ECDH key agreement. Security analysis showed that the proposed protocol can validate the data integrity and resist the replay attack, the man-in-middle attack, and other attacks. Performance analysis and experiments showed that the protocol achieves high security with low communication and computation costs, and can be implemented in smart home systems.