高效率的非交互OT_n^k协议及其应用

An Efficient Non-Interactive OT_n^k Protocol and Its Application

在Cheng-Kang Chu和Wen-Guey Tzeng设计的OTnk协议的基础上提出了一个非交互的OTkn协议.该协议降低了通信复杂度和计算复杂度,接收方的安全性是无条件的,发送方的安全性在判定Diffie-Hellman问题假设下是计算安全的;相比Cheng-Kang Chu和Wen-Guey Tzeng的OTnk协议效率更高.同时修正和给出协议安全性的完整证明.基于所提出的非交互OTnk协议设计了一个数字产品秘密交易机制,解决了产品价格不一致时的数字产品交易问题.

The scheme OTn^k developed by Cheng-Kang Chu and Wen-Guey Tzeng was thought of more efficiency in the congeneric protocols. A non-interactive k-out-of-n oblivious transfer protocol OTn^k is presented, improved with the scheme of Chu and Tzeng. In the proposed protocol, the sender S sends O（n） messages to a receiver R, but R does not send any messages back to S. In other words, R is non-interactive with S. This scheme is proved to be more efficient than that developed by Chu and Tzeng. The receiver＇s choices are unconditionally secure. The secrecy of the sender＇s unchosen messages is guaranteed if the decisional Diffie-Hellman problem is hard. The security proof of the proposed protocol has also consummated. An example of oblivious transfer protocols＇ application such as a private transaction mechanism of digital productions is presented by employing the proposed scheme. The problems when all productions are different prices have been solved.