TWC: Small: New Advances for Efficiently-Searchable Encryption

目前的全球趋势是远程数据存储解决方案，如云存储，其中不安全的网络上的大量数据存储必须能够有效地访问，并且日益增长的安全要求强调需要支持在大型加密数据库上的高效搜索功能。可搜索加密是一种兼顾效率、功能和安全性的行为。这些解决方案要么需要广泛的交互和计算，对每个查询进行线性数据扫描，这对于大型数据库来说是令人望而却步的，要么需要事先知道所有数据。本研究通过三个关键领域来推进高效可搜索加密(ESE)的发展：保序加密的新安全保证，模糊查询的可搜索加密，以及寻找ESE的一般定义。PI进行了一项保序加密的密码学研究，以支持对远程加密数据的高效范围查询。该项目澄清了先前定义的安全保障，并研究了替代环境，以制定新的安全解决方案。本研究的重点是模糊查询，它返回与接近底层查询消息的消息相对应的数据库元素。这项工作开启了模糊可搜索加密(FSE)的第一个形式化密码学研究。特别是，这项工作的重点是制定适当的安全定义和建立可证明安全的FSE方案。这项研究寻求一个涵盖所有已知类型的ESE的一般定义，并调查相关的不可能性问题。该研究将各种ESE的安全定义扩展到数据库的整体安全。

Current worldwide trends towards remote data storage solutions such as cloud storage, in which large stores of data on insecure networks must be efficiently accessible, and increasing security requirements emphasized the need to support efficient search functionality on large encrypted databases. Searchable encryption is a balancing act of efficiency, functionality, and security. The solutions either require extensive interaction and computation, linear data scan on each query, which is prohibitive for large databases, or knowing all data in advance. This research advances the state of the art of efficiently-searchable encryption (ESE) by focusing on three key areas: new security guarantees for order-preserving encryption, searchable encryption for fuzzy queries, and seeking a general definition of ESE. The PI has conducted a cryptographic study of order-preserving encryption for supporting efficient range queries on remote encrypted data. This project clarifies the security guarantees of the previous definition and studies the alternative settings in order to develop new secure solutions. This research focuses on fuzzy queries which return database elements that correspond to messages which are close to the underlying queried message. This work initiates the first formal cryptographic study of fuzzy searchable encryption (FSE). In particular, the work focuses on developing appropriate security definitions and building provably-secure FSE schemes. This research seeks a general definition that will cover all known types of ESE, and investigates related impossibility issues. The research extends security definitions for various ESE to security of the database as a whole.