中文摘要：

针对现有解决方案计算复杂度高、编码规模大以及因明文数量限制而导致的密文碰撞的安全问题,利用基于OBDD的安全函数评估协议和加法同态加密机制,提出一个新的多方信息安全比较相等协议,并分析了该协议的安全性、正确性和效率。该协议对参与者的私有信息采用常规的二进制编码,利用基于OBDD的安全函数评估协议对参与者的私有信息进行评估,并利用加法同态加密机制计算具有相等私有信息的参与者数目。与已有解决方案相比,该协议不仅降低了计算复杂度,而且弥补了已有解决方案存在的安全问题,并具有良好的可扩展性。

英文摘要：

Based on the secure function evaluation with OBDD and semantic addition homomorphic encryption, a new protocol of multi-party secure comparing is proposed. The new protocol uses the binary coding to encode the private in- formation and uses the secure function evaluation with OBDD to evaluate them. After that, the new protocol gets the number of users who has the same inputs by the addition homomorphie encryption. The correctness, security and efficiency of the new protocol are analyzed. Compared with the existing solution, the new protocol reduces the computational complexity, fix the security problem and has good scalability.