论文标题
使用受信任的执行加速前进和向后私人可搜索的加密
Accelerating Forward and Backward Private Searchable Encryption Using Trusted Execution
论文作者
论文摘要
可搜索的加密(SE)是构建加密数据库的关键推动因素之一。它允许云服务器无需解密即可搜索加密数据。动态SE还包括数据添加和删除操作,以丰富加密数据库的功能。开发动态操作中泄漏的最新攻击推动了新的SE方案的快速开发,在执行更新时揭示了较少的信息;它们也被称为前向和落后SE。新添加的数据不再可链接到之前发出的查询,并且在以后发布的查询中不再搜索已删除的数据。但是,这些高级SE方案降低了SE的效率,尤其是在客户端和服务器之间的通信成本中。在本文中,我们求助于硬件辅助解决方案,也就是Intel SGX,以简化上述瓶颈。我们的关键想法是利用SGX接管客户端的大多数任务,即跟踪关键字状态以及数据添加和缓存删除数据。但是,由于SGX飞地的I/O和内存约束,处理大型数据集并非平凡。我们进一步开发了批处理数据处理和状态压缩技术,以减少SGX和不信任服务器之间的通信开销,并最大程度地减少飞地中的内存足迹。我们对合成和现实世界数据集进行了一系列全面的评估,这些评估确认我们的设计表现优于先前的艺术。
Searchable encryption (SE) is one of the key enablers for building encrypted databases. It allows a cloud server to search over encrypted data without decryption. Dynamic SE additionally includes data addition and deletion operations to enrich the functions of encrypted databases. Recent attacks exploiting the leakage in dynamic operations drive rapid development of new SE schemes revealing less information while performing updates; they are also known as forward and backward private SE. Newly added data is no longer linkable to queries issued before, and deleted data is no longer searchable in queries issued later. However, those advanced SE schemes reduce the efficiency of SE, especially in the communication cost between the client and server. In this paper, we resort to the hardware-assisted solution, aka Intel SGX, to ease the above bottleneck. Our key idea is to leverage SGX to take over the most tasks of the client, i.e., tracking keyword states along with data addition and caching deleted data. However, handling large datasets is non-trivial due to the I/O and memory constraints of the SGX enclave. We further develop batch data processing and state compression technique to reduce the communication overhead between the SGX and untrusted server, and minimise the memory footprint in the enclave. We conduct a comprehensive set of evaluations on both synthetic and real-world datasets, which confirm that our designs outperform the prior art.