通过USB存储插入实现可审计且透明的全认证磁盘加密
Auditable and Transparent Fully Authenticated Disk Encryption via USB Storage Interposition
浏览论文内容
中文总结 AI 辅助
研究探索通过在主机与外部硬盘间插入支持USB On-The-Go的通用单板计算机实现全认证磁盘加密，设计了CC系统，该系统具灵活性、低成本等优势，经实验评估对多数常见用例效率足够高。
中文摘要 AI 辅助
在过去几十年中，由于明显的保密性问题，全磁盘加密（FDE）变得越来越重要。在大多数系统中，加密由操作系统驱动程序提供，用户提供所需密钥（或从中派生密钥的凭证）后可以透明地访问加密磁盘。在这项工作中，我们探索了一种替代方法：在主机系统和存储加密数据的外部硬盘之间使用中间USB设备。虽然有现有的设备采用这种内联方法（如RAID控制器和内置加密的USB外壳），但我们探索使用运行Linux且支持USB On-The-Go的通用单板计算机（如树莓派）来提供全认证磁盘加密（FADE）。我们的系统名为CC（加密伴侣），执行加密操作（加密/解密和认证），为主机提供标准USB大容量存储接口（主机完全不知道加密的存在），同时依靠外部USB硬盘存储相应的加密块。我们的设计具有几个关键优势：灵活性、低成本、透明性、使用通用硬件和免费开源软件、适应新兴加密方案以及抵御恶意磁盘固件。本文介绍了CC的设计和实现以及对当前研究原型的实验评估，表明它对大多数常见用例来说效率足够高。
英文摘要
Full Disk Encryption (FDE) has become increasingly important in the last decades due to the evident confidentiality concerns. In most systems, encryption is provided by an operating system driver, through which the user can transparently access the encrypted disk after supplying the required keys (or the credentials from which those keys are derived). In this work, we explore an alternative approach: the use of an intermediate USB device placed between the host system and the external hard disk, where the encrypted data are stored. Although there are existing devices that follow this inline approach (such as RAID controllers and USB enclosures with built-in encryption), we explore the use of a general-purpose single-board computer running Linux with USB On-The-Go support (e.g. a Raspberry Pi), to provide FADE (Fully Authenticated Disk Encryption). Our system, named CC (Cryptographic Companion), performs the cryptographic operations (encryption/decryption and authentication), providing a standard USB mass-storage interface to the host (which is entirely unaware of the presence of encryption) while relying on the external USB hard disk to store the corresponding encrypted blocks. Our design provides several key advantages: flexibility, low cost, transparency, the use of generic hardware and free and open-source software, adaptability to emerging cryptographic schemes, and mitigations against malicious disk firmware. This paper presents the design and implementation of the CC and an experimental evaluation of our current research prototype, which indicates that it is sufficiently efficient for most common use cases.
