The shortest distance query is used to determine the shortest distance between two vertices. Various graph encryption schemes have been proposed to achieve accurate, efficient and secure shortest distance queries for encrypted graphs. However, the majority of these schemes are inefficient or lack scalability due to the time-consuming index construction and large index storage. Moreover, none of them consider the trade-off between query efficiency and accuracy. To better trade off the query efficiency and accuracy, we propose a Pruned Pendant Vertex based Index for Shortest Distance Query ( $\mathsf { PPVI}$ - $\mathsf { SDQ}$ ) under structured encryption. The proposed scheme utilizes the structured encryption technique to encrypt a graph and build indexes. The main idea is to use the recursive method to repeatedly prune the pendant vertex, and thereby reducing the index size and construction time by minimizing the redundant data storage and graph traversal. The proposed scheme achieves accurate, efficient and secure shortest distance query with privacy-preserving for encrypted graph. The security analysis demonstrates that the proposed scheme satisfies CQA2-security. Experimental results with real datasets show that the scheme achieves the optimal accuracy and efficiency.

中文翻译：

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结构化加密图下基于剪枝悬垂顶点的最短距离查询索引


最短距离查询用于确定两个顶点之间的最短距离。为了实现加密图准确、高效、安全的最短距离查询，人们提出了各种图加密方案。然而，由于索引构建耗时且索引存储量大，这些方案大多数效率低下或缺乏可扩展性。而且，他们都没有考虑查询效率和准确性之间的权衡。为了更好地权衡查询效率和准确性，我们提出了一种基于结构化加密下的最短距离查询的剪枝悬垂顶点索引（ $\mathsf { PPVI}$ - $\mathsf { SDQ}$ ）。所提出的方案利用结构化加密技术来加密图并建立索引。主要思想是利用递归的方法对下垂顶点进行反复剪枝，从而通过最小化冗余数据存储和图遍历来减少索引大小和构建时间。该方案实现了加密图的准确、高效、安全且隐私保护的最短距离查询。安全性分析表明该方案满足CQA2-安全性。真实数据集的实验结果表明，该方案达到了最优的精度和效率。