As cloud computing becomes prevalent, more and more data owners are likely to outsource their data to a cloud server. However, to ensure privacy, the data should be encrypted before outsourcing. Symmetric searchable encryption allows users to retrieve keyword over encrypted data without decrypting the data. Many existing schemes that are based on symmetric searchable encryption only support single keyword search, conjunctive keywords search, multiple keywords search, or single phrase search. However, some schemes, i.e., static schemes, only search one phrase in a query request. In this paper, we propose a multi-phrase ranked search over encrypted cloud data, which also supports dynamic update operations, such as adding or deleting files. We used an inverted index to record the locations of keywords and to judge whether the phrase appears. This index can search for keywords efficiently. In order to rank the results and protect the privacy of relevance score, the relevance score evaluation model is used in searching process on client-side. Also, the special construction of the index makes the scheme dynamic. The data owner can update the cloud data at very little cost. Security analyses and extensive experiments were conducted to demonstrate the safety and efficiency of the proposed scheme.

中文翻译：

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基于对称可搜索加密的加密数据动态多短语排序搜索

随着云计算变得流行，越来越多的数据所有者可能将他们的数据外包给云服务器。但是，为确保隐私，数据应在外包前进行加密。对称可搜索加密允许用户在不解密数据的情况下检索加密数据上的关键字。现有的许多基于对称可搜索加密的方案仅支持单关键字搜索、联合关键字搜索、多关键字搜索或单词组搜索。然而，一些方案，即静态方案，在一个查询请求中只搜索一个词组。在本文中，我们提出了一种对加密云数据的多短语排序搜索，它还支持动态更新操作，例如添加或删除文件。我们使用倒排索引来记录关键字的位置并判断该短语是否出现。该索引可以有效地搜索关键字。为了对结果进行排序并保护相关性分数的隐私，在客户端搜索过程中使用了相关性分数评估模型。此外，索引的特殊构造使方案具有动态性。数据所有者可以以极低的成本更新云数据。进行了安全分析和广泛的实验，以证明所提出方案的安全性和效率。