基于语义分组的动态可搜索加密方案

Dynamic Searchable Encryption Scheme Based on Semantic Grouping

为满足用户对云端文档动态更新的需求,支持动态更新的可搜索加密方案成为了研究热点.但目前已知方案对于索引结构的更新多采用尾部直接插入的方法,造成了新添加关键字和文档之间关联性的泄露.为此本文提出一种基于语义分组的动态可搜索加密方案.首先构建分组平衡二叉树作为索引结构,通过语义分组减少搜索时访问的节点数,提高搜索效率.然后结合分区矩阵的思想,在矩阵中添加虚拟关键字保证更新时的安全性.最后通过形式化的证明分析了本文方案的安全性.

Searchable encryption scheme supporting dynamic update has become a research hotspot to meet the needs of users for dynamic update of cloud documents. However, most of the known schemes update the index structure by the direct insertion at the tail, which leads to the leakage of the relationship between the newly added keywords and the document. Therefore, this study proposes a dynamic searchable encryption scheme based on semantic grouping. Firstly,the balanced binary tree is constructed as the index structure, and the number of nodes is reduced by semantic grouping for search efficiency improvement. Then, in light of the idea of partition matrix, virtual keywords are added to the matrix to ensure the security of update. Finally, the security of the scheme is analyzed by formal proof.