| 摘要: |
| 群签名作为一种隐私保护的重要技术, 为用户匿名性提供良好的保障. 然而, 普通群签名方案存在可追溯签名者身份的群管理员, 与区块链去中心化的特性相悖, 难以满足对于隐私性要求更严格的应用场景. 结合防双重认证签名技术, 提出一种具有用户自主链接及验证者条件撤销的群签名, 较好地实现了用户隐私与平台管理之间的平衡, 并给出了格上实例化方案. 通过随机谕言机模型下的安全性分析, 方案满足无私匿名性、可追溯性和不可诽谤性. 通过性能分析, 方案的时间开销和通信开销均在可接受范围内. 最后, 设计了一种基于区块链的后量子安全医疗数据共享条件隐私保护系统, 给出方案的具体应用实例. |
| 关键词: 群签名 后量子密码 区块链 条件隐私保护 格密码 |
| DOI：10.13328/j.cnki.jos.007390 |
| 分类号:TP309 |
| 基金项目:国家重点研发计划 (2022YFB4400700); 国家自然科学基金 (62325209, 62172307, U23A20302); 中央高校基本科研业务费专项资金 (2042023KF0203, 2042024kf1013, 2042024kf0002) |
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| Lattice-based Group Signatures with User-controlled Linkability and Verifier Conditional Revocation |
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CHEN Ying, HE De-Biao, PENG Cong, LUO Min
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Key Laboratory of Aerospace Information Security and Trusted Computing (Wuhan University), Wuhan 430072, China
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| Abstract: |
| Recognized as a crucial privacy-protecting technology, group signatures provide robust anonymity assurances for users. However, conventional group signature schemes often rely on group managers capable of revealing the identities of signers, a feature that contradicts the decentralized nature of blockchain and fails to meet stricter privacy demands in certain applications. To address these limitations, this study introduces a group signature scheme with user-controlled linkability and verifier conditional revocation, inspired by double-authentication-preventing signatures and existing linkable and revocable group signatures. The proposed scheme achieves an optimal balance between user privacy and platform oversight, with a concrete instantiation constructed on lattices. Under the random oracle model, the scheme is demonstrated to satisfy the properties of selfless anonymity, traceability, and non-frameability. Performance evaluations indicate that both time and communication costs remain within acceptable limits, ensuring feasibility for practical deployment. In addition, a post-quantum secure medical data sharing system has been designed, integrating the proposed group signature scheme with blockchain technology. |
| Key words: group signature post-quantum cryptography blockchain conditional privacy protection lattice |
