Abstract: In order to cope with the challenge of privacy leakage of identity information and transaction data in the federation chain, a privacy protection method for consortium blockchain based on SM2 linkable ring signature (PPMCB-SM2LRS) is proposed. First, for the problems of insufficient security and poor traceability of the linkable ring signature scheme, it is redesigned in combination with SM2 digital signature, aiming to enhance the privacy protection of the identity of the counterparty and at the same time to be able to trace back the evil transaction users. Second, based on the optimized Paillier homomorphic encryption algorithm, a hierarchical encryption strategy is proposed to realize the "visible unavailability" of private data, so as to improve the privacy and confidentiality of transaction data verification in the federation chain. The security analysis shows that the proposed method is correct, unforgeable, conditionally anonymous and linkable. The experimental results show that compared with the same type of linkable ring signature scheme, the average consumption time of the signature generation phase and the signature confirmation phase are shortened by 19.3% and 18.7%, respectively, which is in line with the principle of autonomy and controllability in the development of cryptographic technology

Key words: privacy protection, consortium blockchain, SM2 digital signature, linkable ring signature, Paillier homomorphic

摘要： 摘 要: 为应对联盟链中身份信息和交易数据隐私泄露的挑战，提出一种基于SM2可链接环签名的联盟链隐私保护方法(PPMCB-SM2LRS)。首先，针对可链接环签名方案存在安全性不足、追溯性差的问题，结合SM2数字签名对其重新设计，旨在增强交易方身份隐私保护的同时能够对作恶的交易用户进行追溯。；其次，基于优化后的Paillier同态加密算法提出一种分级加密策略，实现隐私数据的“可见不可用”，以提高联盟链中交易数据验证的隐私性和机密性。安全性分析表明，所提方法具备正确性、不可伪造性、条件匿名性和可链接性。实验结果表明，与同类型可链接环签名方案相比，PPMCB-SM2LRS具有更小的计算开销，且在签名生成阶段与和签名确认阶段的平均消耗时有间分别缩短了27.2%和18.7%显著降低，同时并符合密码技术发展的自主可控性原则。

关键词: 隐私保护, 联盟链, SM2数字签名, 可链接环签名, Paillier同态加密