三方不经意多项式求值协议

Three-party oblivious polynomial evaluation protocol

针对多方计算中的隐私保护问题,提出一种三方不经意多项式求值协议。协议拥有3个参与者,分别为一个发送者和两个接收者,发送者拥有一个二元多项式P(x,y),两个接收者分别拥有α和β。该协议通过使用Diffie-Hellman密钥交换协议和任意一种安全的不经意传输协议来实现,完成如下目标:接收者得到P(α,β)的值,但无法得到关于多项式P的任何信息,发送者无法得到关于α和β的任何信息。理论分析结果表明了协议的正确性和对发送者、接收者的安全性,给出了该协议在两方Hamming距离安全计算中的应用,拓展了不经意传输协议的使用范围,为安全多方计算的实现提供了一种新途径。

Aiming at the problem of privacy protection in the multi-party computation,a three-party oblivious polynomial evaluation protocol was proposed.There were three parties in the protocol,a sender who had a bivariate polynomial P（x,y）,and two receivers who had the values ofαandβrespectively.The Diffie-Hellman key exchange protocol and a secure oblivious transfer protocol were used to achieve the goal that the receivers can only get the value of P（α,β）but nothing else about the polynomial P,and the sender cannot access any information aboutαandβ.Through theoretical analysis,the protocol is proved to be correct and secure for both the sender and receivers.An application of the protocol in the two-party secure hamming distance computation is given.The protocol expands the use of oblivious transfer protocols,and provides a new way for multi-party security computation.