Constant-Round Client-Aided Secure Comparison Protocol
Constant-Round Client-Aided Secure Comparison Protocol
复制标题
恒定循环客户端辅助安全比较协议
DOI：
10.1007/978-3-319-98989-1_20
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Goichiro Hanaoka
中科院分区：
文献类型：
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作者：
Hiraku Morita;Nuttapong Attrapadung;Tadanori Teruya;Satsuya Ohata;K. Nuida;Goichiro Hanaoka
整数比较是安全计算中最基本的组成部分之一，我们针对整数比较功能提出了一种改进的常轮安全两方协议。我们的协议是所谓的客户端-服务器模型，它被用于现实世界的MPC产品，如Sharemind，其中任何数量的客户端都可以创建他们输入的份额并分发给服务器，然后服务器共同计算份额并将结果的份额返回给客户端。在client-aidedclient-server模型中，正如Mohassel和Zhang （S&P’17）简要提到的，客户端进一步生成一些必要的相关随机性，并将其分发给服务器。这种相关的随机性允许有效的协议，否则服务器必须自己联合生成随机性，这可能是低效的。在本文中，我们改进了damg<s:1>等人（TCC ' 06）和Nishide和Ohta （PKC ' 07）在客户端辅助模型中的最先进的恒轮比较协议。我们的技术包括识别这些比较协议中的相关随机性。在此过程中，我们还将基于树的技术用于构建块，这与上述两个作品有所不同。无论输入的比特长度如何，我们提出的协议只需要5轮通信。这至少比现有协议少5轮。我们在c++中实现了安全比较协议。我们的实验结果表明，这种低轮复杂度有利于低延迟网络，如广域网。
We present an improved constant-round secure two-party protocol for integer comparison functionality, which is one of the most fundamental building blocks in secure computation.Our protocol is in the so-calledclient-server model, which is utilized in real-world MPC products such as Sharemind, where any number of clients can create shares of their input and distribute to the servers who then jointly compute over the shares and return the shares of result to the client. In theclient-aidedclient-server model, as mentioned briefly by Mohassel and Zhang (S&P’17), a client further generates and distributes some necessary correlated randomness to servers. Such correlated randomness admits efficient protocols since otherwise servers have to jointly generate randomness by themselves, which can be inefficient.In this paper, we improve the state-of-the-art constant-round comparison protocols by Damgård et al. (TCC’06) and Nishide and Ohta (PKC’07) in the client-aided model. Our techniques include identifying correlated randomness in these comparison protocols. Along the way, we also use tree-based techniques for a building block, which deviate from the above two works. Our proposed protocol requires only 5 communication rounds, regardless of the bit length of inputs. This is at least 5 times fewer rounds than existing protocols. We implement our secure comparison protocol in C++. Our experimental results show that this low-round complexity benefits in low-latency networks such as WAN.