抗内部关键词猜测攻击的高效公钥可搜索加密方案

Efficient Public-key Searchable Encryption Scheme Against Inside Keyword Guessing Attack

云环境下,如何对用户加密数据实现高效检索是学术界的研究热点。现有大部分公钥可搜索加密方案不能有效抵御由云服务器发起的内部关键词猜测攻击(Inside Keyword Guessing Attack,IKGA),而抗IKGA方案存在效率不高,以及相同关键词对应搜索陷门相同导致的关键词统计信息泄露等问题。鉴于此,提出了一个新的高效抗IKGA的公钥可搜索加密方案,并基于变形DLIN(Decision Linear Problem)假设,以随机预言机模型证明了新方案满足内部关键词猜测攻击下的语义安全。新方案中,搜索陷门包含随机数且相同关键词的搜索陷门不同。与其他PEKS方案相比,新方案减少了双线性对运算的使用次数,因此具有更大的性能优势。

In the cloud environment,how to search users’encrypted data efficiently is the research hotspot in academic circle.Most current public-key searchable encryption schemes cannot effectively resist the Inside Keyword Guessing Attack(IKGA)launched by cloud servers,while the existing anti-IKGA schemes suffer the problems of low efficiency or the same search trapdoors generation algorithm for same keyword,which would reveal statistics information of keywords.This paper proposed a new efficient anti-IKGA public-key searchable encryption scheme,in which the search trapdoor is generated by a non-deterministic algorithm.Based on the modified DLIN(Decision Linear Problem)assumption,the new scheme is certified to satisfy semantic security against IKGA in the random oracle model.In the new scheme,the trapdoors are generated with random numbers thus same keyword has various trapdoors.Compared with other PEKS schemes,the new scheme reduces the number of bilinear pairing operations and thus has better performance advantages.