中文摘要：

鉴于目前已有的隐私保护的线段相交判定协议的参与方都是两方,不能解决多方之间判定线段是否相交的问题,因此提出了一个隐私保护的四方相互合作判定线段是否相交的协议。4个参与方各自拥有线段的一个端点,采用安全多方计算中的一些基础运算协议,通过两两计算,判定由这4个端点构成的两条线段是否相交,同时确保不会向其它的参与方泄漏线段以及端点的信息。最后给出了该协议在现实中的一个应用。

英文摘要：

In consideration of existing protocols on privacy-preserving deciding the intersection of line segments are executed by two-party,which can not solve that executed by multi-party,a privacy-preserving protocol on deciding the intersection of line segments is put forward by four-party,each party provides with a point,uses some secure multi-party elementary function computation protocols,through mutual-computation,decides whether the two line segments including above four points are intersectant,while insure no infor-mation of the points and line segments are leaked to the other party,and lastly its one application is given in the real world.