Abstract: Smart home systems have been widely popularized  in people’s daily lives. However, due to the limited computational resources of smart home nodes, numerous issues still exist in achieving privacy protection and key management. To enhance the security of smart home systems, a lightweight signature scheme has been designed. This scheme is constructed based on the SM2 cryptographic algorithm and two-party collaborative signing, with key splitting and storage implemented to reduce the risk of key leakage. Meanwhile, the key generation process is integrated with user registration, and authentication parameters are added during the interaction between users and smart gateways  for private key generation, thereby further improving the system security without the need to synthesize a complete private key during the signing phase. Finally, security proofs are provided, including unforgeability, anonymity, and storage security. The results of simulated experiments  demonstrate that the designed signature scheme is suitable for smart home systems in lightweight environments.

Key words: smart home system, two-party collaborative signature, public key cryptographic algorithm SM2 based on elliptic curve, key splitting