【摘要】 针对现有方案在差异化隐私保护场景下仅支持粗粒度的属性保护策略，提出了一种基于多级承诺协议的身份认证隐私保护方案（Iascb-Mcp），旨在允许用户根据需求选择性地公开或保密其属性信息，以满足不同隐私场景下的保护需求。该方案通过多级承诺结构实现对用户属性的保护。首先，每个用户属性被分配一个隐私等级，根据隐私等级设计了相应的承诺协议。其次，根据不同隐私级别的用户属性采用不同的身份验证方式，利用零知识证明确保在用户高隐私级别属性不暴露的情况下仍能进行有效身份认证。最后，利用Iascb-Mcp方案构建了一个基于联盟链身份验证的系统，解决了链下用户属性的隐私验证以及链上不同群组之间交易的安全性问题。安全分析与实验结果表明，在身份认证过程中其他用户无法获取证明者的高隐私级别属性；与群签名方案相比，Iascb-Mcp的验证时间降至1～3s；与双环签名方案相比，新生成的证明文件大小是原文件大小的1/10左右。更多还原

【Abstract】 As existing schemes only support coarse-grained attribute protection policies in differentiated privacy protection scenarios,an identity authentication privacy protection scheme based on multi-level commitment protocol(Iascb-Mcp)is proposed in this paper,which aims to allow users to selectively disclose or keep secret their attribute information according to requirements,so as to meet the protection requirements in different privacy scenarios.The scheme realizes the protection of user attributes through multi-level commitment structure.First,each user attribute is assigned a privacy level,and the corresponding commitment protocol is designed according to the privacy level.Secondly,different authentication methods are adopted according to the user attributes of different privacy levels,and zero-knowledge proof is used to ensure that the user’s high privacy attributes can still be effectively authenticated without being exposed.Finally,the Iascb-Mcp scheme is used to construct a system based on alliance chain authentication,which solves the privacy authentication of off-chain user attributes and the security of transactions between different groups on the chain.The results of security analysis and experiment show that other users cannot obtain the high privacy attribute of the prover in the authentication process.Compared with the group signature scheme,the authentication time of Iascb-Mcp is reduced to 1sto 3s.Compared with the two-ring signature scheme,the newly generated proof file is about onetenth of the size of the original file.更多还原