支持联合查询的高效可搜索对称加密方案

Efficient Searchable Symmetric Encryption for Conjunctive Queries

采用基于Diffie-Hellman类型操作的安全两方计算实现的OXT方案是目前支持联合查询的最优可搜索对称加密方案,但Diffie-Hellman类型操作计算开销大,将成为该方案的计算性能瓶颈.为了提高计算性能,提出一个支持联合查询的高效可搜索对称加密方案(EXT方案).该方案采用客户端单独计算关键字与文档之间的关系,并交给服务器检验该关系的方法来实现联合查询,从而避免了Diffie-Hellman类型操作.并从正确性、安全性以及性能方面对EXT方案进行分析.分析结果表明:与OXT方案相比较,EXT方案将系统初始化的计算量、查询时客户端的计算量、查询时服务器的计算量、存储开销分别降低了95.05%、97.67%、98.48%、55.05%.

OXT,which uses the Diffie-Hellman-type-operation-based secure two-party computation,is the state-of-the-art searchable symmetric encryption(SSE)scheme supporting conjunctive queries.However,the Diffie-Hellman-type operation is computationally expensive and may lead to a performance bottleneck.In order to improve the computational performance,an efficient searchable symmetric encryption scheme EXT which supports conjunctive queries is proposed.EXT uses a framework different from OXT to support conjunctive queries,where the client computes relations between keywords and documents independently,and the server only checks all these relations.Hence,no Diffie-Hellman operations are required for EXT.Furthermore,EXT is analyzed in terms of correctness,security,and performance.Compared with OXT,EXT reduces the setup computational cost,the client's computational cost,the server's computational cost,and the storage size by 95.05%,97.67%,98.48%and 55.05%,respectively.