Secure Multi-party SM2 Signature Based on SPDZ Protocol

Nowadays, the demand for signing and verifying data in various fields is getting higher and higher, and digital signature schemes need to be adapted to two-party or even multi-party and multi-device scenarios. To meet the needs of multi-party signature scenarios, we propose a multi-party SM2 signature scheme based on SPDZ protocol. The basic signature scheme used in this paper is the SM2 digital signature algorithm in the standard “SM2 Elliptic Curve Public Key Cryptography” of ISO/IEC14888-3, which has the advantages of high security and reliability as well as efficient signature speeds. Our scheme allows multiple participants to jointly sign a message while resisting up to \(n-1\) malicious corrupted parties in dishonest-majority settings. Compared to existing schemes against malicious adversaries, our scheme discards costly zero-knowledge proofs in favor of low-overhead MACs, which reduces the computational and communication complexity of multi-party signatures. We analyze the security and performance evaluation of the scheme, and the results show that the scheme has high efficiency while ensuring security.