Cut-and-Choose双向不经意传输

Cut-and-Choose Bilateral Oblivious Transfer

不经意传输作为现代密码学的一个基本工具,在安全协议的研究中起着重要作用.近年来,许多功能性更强的不经意传输变种被提出来,以适应不同的需求和环境.提出一个不经意传输变种,称为cut-and-choose双向不经意传输.基于同态加密给出该原语的一轮高效协议构造,且在半诚实模型下形式化证明了该协议的安全性.将cut-and-choose双向不经意传输运用到基于cut-and-choose技术的安全协议(尤其是安全两方计算)中,可以更具模块化地描述协议高层框架,降低协议交互轮数.此外,作为信息安全领域的一个底层基本工具,该原语本身也具有独立的研究意义.

Oblivious transfer is a fundamental tool in modern cryptography. It plays an important role in the research of security protocols. In recent years, many oblivious transfer variants with more powerful functionalities are proposed to fit in different kinds of requirements and scenarios. In this paper, a new oblivious transfer variant, called cut-and-choose bilateral oblivious transfer, is proposed. Based on homomorphic encryption, an efficient one-round protocol of this primitive is constructed along with rigorous security proof in semi-honest model. When applied in security protocols based on cut-and-choose technique（especially in secure two-party computation）, cut-and-choose bilateral oblivious transfer enables a more modular high-level description of the protocol framework, and also reduces the round complexity of the protocols. Besides, as a basic tool in the information security area, this primitive itself is of independent research interest.