跨服务提供商的联邦匿名黑名单及其在群组消息中的应用
Federated Anonymous Blocklisting across Service Providers and its Application to Group Messaging
AI总结：
本文提出联邦匿名黑名单方案，通过分布式Realm替代中心化服务提供商，实现匿名用户身份验证，提升群组消息安全性。
摘要：
即时通讯已成为在线通信中最常用的通信方式之一，其底层加密协议和安全保证也引起了广泛关注。为提高隐私而引入的端到端加密和伪名等技术已得到应用。然而，如消息群组等在线空间仍需要管理以防止不良用户参与，特别是在匿名场景中。在匿名黑名单（AB）方案中，用户必须在认证过程中证明其之前使用的伪名未被阻止，从而防止不良用户创建新的伪名。在本工作中，我们提出了一种替代方案，即联邦匿名黑名单（FAB），其中中央化的服务提供商被小型分布式Realm取代，每个Realm都有自己的黑名单。Realm之间可以建立信任关系，使得当用户认证到一个Realm时，必须证明其在任何受信任的Realm中均未被阻止。我们实现了所提出的方案；与现有AB构造不同，我们的方案性能不依赖于当前黑名单的大小，也不需要处理新添加到黑名单中的条目。我们还通过将我们的FAB方案整合到消息层安全协议中，展示了其在现实世界消息群组中的适用性。
英文摘要：
Instant messaging has become one of the most used methods of communication online, which has attracted significant attention to its underlying cryptographic protocols and security guarantees. Techniques to increase privacy such as End-to-End Encryption and pseudonyms have been introduced. However, online spaces such as messaging groups still require moderation to prevent misbehaving users from participating in them, particularly in anonymous contexts.. In Anonymous Blocklisting (AB) schemes, users must prove during authentication that none of their previous pseudonyms has been blocked, preventing misbehaving users from creating new pseudonyms. In this work we propose an alternative Federated Anonymous Blocklisting (FAB) in which the centralised Service Provider is replaced by small distributed Realms, each with its own blocklist. Realms can establish trust relationships between each other, such that when users authenticate to a realm, they must prove that they are not blocked in any of its trusted realms. We provide an implementation of our proposed scheme; unlike existing AB constructions, the performance of ours does not depend on the current size of the blocklist nor requires processing new additions to the blocklist. We also demonstrate its applicability to real-world messaging groups by integrating our FAB scheme into the Messaging Layer Security protocol.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
