论文标题
完全安全的同步MPC，并具有异步后备的一般对手的保证
Perfectly Secure Synchronous MPC with Asynchronous Fallback Guarantees Against General Adversaries
论文作者
论文摘要
在这项工作中，我们研究了针对一般（非阈值）对手的完美安全多方计算（MPC）。同步网络中的已知协议可针对$ q^{（3）} $对抗结构安全，而在异步网络中，已知的协议可针对$ q^{（4）} $对抗结构进行安全。一个自然的问题是，是否存在单个协议，该协议与$ q^{（3）} $和$ q^{（4）} $对抗结构分别分别在同步网络中，当事方不知道网络类型。我们针对一般对手设计了第一个这样的最佳世界问题协议。我们的结果概括了Appan，Chandramouli和Choudhury（PODC 2022）的结果，该结果呈现出针对阈值对手的最佳全球完美安全方案。 为了设计我们的协议，我们提出了两个重要的构件，它们具有独立的兴趣。第一个构建块是针对$ q^{（3）} $对抗结构的最佳both-worlds byzantine协议（BA）协议（BA）协议，在同步和异步网络中保持安全。第二个构建块是一个最佳的both-worlds完美安全可验证的秘密共享（VSS）协议，该协议在同步网络和异步网络中的$ q^{（3）} $和$ q^{（3）} $和$ q^{（4）} $对抗结构保持安全。
In this work, we study perfectly-secure multi-party computation (MPC) against general (non-threshold) adversaries. Known protocols in a synchronous network are secure against $Q^{(3)}$ adversary structures, while in an asynchronous network, known protocols are secure against $Q^{(4)}$ adversary structures. A natural question is whether there exists a single protocol which remains secure against $Q^{(3)}$ and $Q^{(4)}$ adversary structures in a synchronous and in an asynchronous network respectively, where the parties are not aware of the network type. We design the first such best-of-both-worlds protocol against general adversaries. Our result generalizes the result of Appan, Chandramouli and Choudhury (PODC 2022), which presents a best-of-both-worlds perfectly-secure protocol against threshold adversaries. To design our protocol, we present two important building blocks which are of independent interest. The first building block is a best-of-both-worlds perfectly-secure Byzantine agreement (BA) protocol for $Q^{(3)}$ adversary structures, which remains secure both in a synchronous, as well as an asynchronous network. The second building block is a best-of-both-worlds perfectly-secure verifiable secret-sharing (VSS) protocol, which remains secure against $Q^{(3)}$ and $Q^{(4)}$ adversary structures in a synchronous network and an asynchronous network respectively.
