【摘要】 不经意传输协议之间的关系及相互转化是无条件安全密码学的研究重点之一.基于保密增强技术,提出了简化21 OTk为UOT单次执行的协议.采用提取器作为保密增强方法,利用少量附加完全随机性比特,获得几乎均匀分布的输出,泄露的信息量至多为2-n-1/2-o(1)比特,只与传送字串长度有关,而与选择的安全参数无关.与利用universalhash函数做为保密增强方法相比,所需传送的信息量和泄露的信息量更少.给出并证明了协议为无条件安全的条件.更多还原

【Abstract】 Reductions among oblivious transfers have a long history in cryptography. This paper describes a 21-OT^k protocol that can be reduced to a single execution of UOT by using privacy amplification with extractors. An extractor allows to efficiently isolate the randomness of some source into virtually-random bits, using a small number of perfectly-random bits as a catalyst. With extractors, less information is transmitted and the leaked information is at most 2^{-n-1/2-o（1）} bits. The conditions under which the protocol is unconditionally secure are investigated.更多还原