Provably secure multi-signature scheme based on the standard SM2 signature scheme

The multi-signature scheme plays a crucial role in addressing trust and authentication challenges in digital transactions and other scenarios by allowing multiple users to sign the same message. Among various signature schemes, the SM2 signature scheme stands out for its exceptional security and efficiency, making it widely adopted in numerous fields. In this paper, we propose the first provably secure multi-signature scheme based on the standard SM2 signature scheme, i.e., the scheme can be reduced to the standard SM2 signature scheme when there is only one signer. We prove that our scheme is existential unforgeability under chosen message attacks in the bijective random oracle model, based on the assumption that the elliptic curve discrete logarithm problem is hard. Compared with the existing multi-signature schemes based on the SM2 signature scheme in the same category, our scheme exhibits improved efficiency in terms of communication delay and computational cost.