针对传统圆与圆的关系判断算法和直线与圆的关系判断算法不能满足安全性要求的问题,在半诚实模型下,利用安全两方点积协议和加法同态加密体制,提出了安全两数和平方计算协议、安全两实数关系判断协议、安全两点距离计算协议和安全点线距离计算协议,并对这些协议进行了正确性、安全性和复杂性的分析.利用这些协议解决保护私有信息的圆-圆关系判定问题和圆-直线关系判定问题.
In computational geometry, circle-circle and line-circle relationship determination problems are important. If the information of circle or line is supplied by different users but no one would like to disclose his or her data to others, so it is called the secure two-party circle computation problem. A secure square of two real numbers sum protocol, a secure two real numbers relation determination protocol, a secure points distance computation protocol and a secure point-line distance computation protocol are proposed altogether by using secure two-party scalar product protocol and additive homomorphic encryption. The correctness, the security and efficiency of the protocols are also analyzed. The circlecircle relation determination problem and line-circle relation determination problem are solved based on these protocols.