The cloud computing technique, which was initially used to mitigate the explosive growth of data, has been required to take both data privacy and users’ query functionality into consideration. Symmetric searchable encryption (SSE) is a popular solution to supporting efficient keyword queries over encrypted data in the cloud. However, most of the existing SSE schemes focus on the exact keyword query and cannot work well when the user only remembers the substring of a keyword, i.e., substring-of-keyword query. This paper aims to investigate this issue by proposing an efficient and privacy-preserving substring-of-keyword query scheme over cloud. First, we employ the position heap technique to design a novel tree-based index to match substrings with corresponding keywords. Then based on the tree-based index, we introduce our substring-of-keyword query scheme, which contains two consecutive phases. The first phase queries the keywords that match a given substring, and the second phase queries the files that match a keyword in which people are really interested. In addition, detailed security analysis and experimental results demonstrate the security and efficiency of our proposed scheme.

最初用于缓解数据爆炸式增长的云计算技术需要兼顾数据隐私和用户查询功能。对称可搜索加密 (SSE) 是一种流行的解决方案，用于支持对云中加密数据的高效关键字查询。然而，现有的SSE方案大多侧重于准确的关键字查询，当用户只记住关键字的子串即substring-of-keyword查询时，效果不佳。本文旨在通过提出一种高效且隐私保护的基于云的关键字子串查询方案来研究这个问题。首先，我们使用位置堆技术来设计一个新的基于树的索引来匹配子串与相应的关键字。然后基于树型索引，我们介绍了我们的关键字子串查询方案，它包含两个连续的阶段。第一阶段查询与给定子字符串匹配的关键字，第二阶段查询与人们真正感兴趣的关键字匹配的文件。此外，详细的安全分析和实验结果证明了我们提出的方案的安全性和效率。