中文摘要：

隐私保护的计算几何问题指的是参与合作的各方在不向其余各方泄漏自己的私有输入数据的情况下，共同合作完成某些计算任务，秘密判定多边形相似是一个特殊的保护隐私的计算几何问题，在很多领域有着重要的应用．秘密判定两组数据是否对应成比例和对应相等对秘密比较多边形相似起着重要的作用．本文在比较相等协议和点积协议的基础上设计了相应的判定协议，分析了协议的正确性、安全性及复杂性，解决了秘密判定多边形相似问题，取得很好的结果．

英文摘要：

Privacy-Preserving computational geometry problem refers to several users computing a cooperative task, where no user pre- fers his private inputs to be disclosed to anyone else. Privately determining polygonal similarity is a special privacy-preserving compu- tational geometry problem and it can be applied in many fields. It plays an important role to privately determine whether two groups of data are correspondingly proportional and equal. Thus, in this paper, a protocol for determining is developed based on equality-testing protocol and scalar product protocol. In addition, the correctness, security and efficiency of the above protocol are analyzed, which successfully solves the problem of privately determining polygonal similarity.