组消息通信中密钥协议的分析与改进
Analysis and Improvements of the Sender Keys Protocol for Group Messaging
摘要：
双方之间和组设置中的消息传递在实践中以及最近在加密社区中都受到了广泛的关注。该领域的主要挑战之一是为组对话构建安全（端到端加密）和高效的消息传递协议。流行的消息应用WhatsApp和Signal使用一种协议，其中成员具有与所有其他组成员共享的单独的\textit{sender keys}，而不是共享单个组密钥。该协议声称提供前向安全保证。然而，尽管它在实践中被广泛采用，但它从未在密码学文献中被正式研究过。在本文中，我们提出了第一个分析的密钥协议，以及一些前瞻性的改进。为此，我们引入了一个新的加密原语，开发了一个基于游戏的安全模型，在被动和主动设置下进行了安全分析，并对协议提出了几项改进。
英文摘要：
Messaging between two parties and in the group setting has enjoyed widespread attention both in practice, and, more recently, from the cryptographic community. One of the main challenges in the area is constructing secure (end-to-end encrypted) and efficient messaging protocols for group conversations. The popular messaging applications WhatsApp and Signal utilise a protocol in which, instead of sharing a single group key, members have individual \textit{sender keys}, which are shared with all other group members. The Sender Keys protocol is claimed to offer forward security guarantees. However, despite its broad adoption in practice, it has never been studied formally in the cryptographic literature. In this paper we present the first analysis of the Sender Keys protocol along with some prospective improvements. To this end, we introduce a new cryptographic primitive, develop a game-based security model, present a security analysis in the passive and active settings, and propose several improvements to the 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。
