基于Paillier和PSI的多关键字可搜索加密方案

围绕多关键字的高效密文搜索和数据安全性保障问题，展开分析与研究，基于同态加密和私有集合交集技术，提出一种面向多关键字的高效的保护搜索模式的可搜索加密方案.该方案使用随机数填充和Paillier同态加密方法构造安全索引和陷门，保护了索引隐私和陷门隐私，进而保护了搜索模式;该方案通过私有集合交集技术进行连接多关键字搜索，搜索中只使用到了乘法和指数运算，与其他方案相比大大提高了效率;安全性和性能分析表明，该方案具有可搜索加密的语义安全性，可以高效地实现对密文的多关键字搜索，且具有良好的计算代价.

Multi-keyword Searchable Encryption Based on Paillier and Private Set Intersection

Efficient multi-keyword ciphertext search and problems of data security protection were researched. Based on Paillier homomorphic encryption and private set intersection(PSI)technique， a multi-keyword searchable encryption scheme was provided， which can search over encrypted files efficiently and protect the search pattern. First， through random number padding and Paillier homomorphic encryption the index privacy and the trapdoor privacy were protected， and the search pattern was further protected. Then， the scheme supports conjunctive multi-keyword search by using PSI. Because only multiplications and exponentiations were used in searching， the proposed scheme is more efficient than others. Security and performance analysis showed that the scheme has the semantic security of searchable encryption and can perform multi-keyword search efficiently with a good computational cost.