对称可搜索加密技术研究进展

云计算作为一种新型计算模式，具有海量资源、动态扩展、按需分配等特点。资源受限的用户可以将计算任务外包给云服务器，在享受高质量数据服务的同时大大降低了本地管理开销。然而，数据外包导致数据所有权与管理权分离，如何保证数据的安全性成为云计算中亟待解决的关键问题。传统的加密技术虽然可以保证数据的机密性，但是在密文中如何执行有意义的检索操作成为一个巨大的挑战。为了保证数据机密性的同时实现密文数据的高效检索，可搜索加密技术应运而生。近年来，可搜索加密方案的设计日趋多样化，旨在提高方案的实用性。该文主要围绕目前可搜索加密方案的研究热点，从4个方面展开阐述，具体包括：单关键词检索、多模式检索、前/后向安全检索和可验证检索。该文主要介绍和分析具有代表性的研究成果，总结最新研究进展及提炼关键技术难点，最后对未来的研究方向进行展望。

Research on Searchable Symmetric Encryption

Cloud computing, as a new computing paradigm, offers dynamically scalable and seemly unbounded storage and computation resources in a pay-as-you-go manner. In order to enjoy superior data services and reduce the local maintenance cost, more and more resource-constrained users prefer to outsource their data to the cloud server. However, outsourcing data to the remote server suffers from data security concerns, because the server may try to learn the information of the outsourced data as much as possible for commercial purpose. The traditional encryption technique can protect the confidentiality of users’ data, however, it leads to the loss of search ability over the encrypted data. Fortunately, searchable encryption, as a promising solution, enables the server to perform keyword-based search over encrypted data. Recently, the design of searchable encryption scheme is becoming more and more diversified, aiming to improve the practicability of the scheme. This paper focuses on the current research for searchable encryption scheme in four aspects, including single keyword search, multi-modal search, forward/ backward secure search and verifiable search. This paper mainly introduces and analyzes the representative research results, summarizes the latest research progress and key technical difficulties, and finally prospects the future research direction.