Securing Data Storage

计算机用户通过各种存储介质（SD卡、USB存储棒、笔记本电脑、电子邮件附件等）存储大量的个人数据和知识产权，而这些用户在存储安全方面没有任何保证。有些技术，如加密，在某些地方使用或用于保护传输，但它们是存储数据的一个方面，而不是与数据相关联的策略。******有许多改进存储的技术，例如加密、安全删除、可否认存储、历史独立性和存储虚拟化。尽管如此，它们经常不一起使用，也没有一个在***实践中被广泛使用。虽然这对某些用户来说不是最优的，但对于在敌对环境中工作的更极端的用户，如军队、记者、***和持不同政见者，它完全失败了。通过将安全性作为标准文件系统的一部分，这项工作将提高存储安全的最低标准。******该研究项目有两大组成部分。其中之一是提高便携式闪存存储的安全性，作为第一道防线。闪存被广泛使用，但它有一个细微的特点：数据不能被***覆盖。相反，新数据被写错了位置，删除只能在大粒度下进行。这对存储、读取和删除数据的算法和文件系统有重要的影响。它还使一些通常很容易提供的安全功能严重复杂化。基于对设计flash文件系统的挑战的深刻理解，本工作将设计下一代flash文件系统，其目标是协调加密，安全删除，可否认性和其他功能，而不会在最终文件系统的可用性和性能方面造成重大损失。******第二个组成部分是开发可用的技术，允许用户指定数据的存储策略，而不必指定要使用的特定存储介质。目前，用户把文件放在u盘上便于携带，或者通过电子邮件发送给自己，以便在其他电脑上访问。用户经常进行临时备份，并将数据存储在多个地方，而不清楚如何存储数据，甚至不清楚数据存储在哪里。目前人们用来保护数据的技术不方便、不安全、不可靠或不可用。我们将创建一个虚拟存储设备（VSD）来解决这些问题。VSD将成为数据进出存储端点的路由器，允许用户专注于他们想要的存储属性，如安全性、速度、可靠性和成本。VSD将从对用户有意义的策略和风险属性中抽象出存储介质的物理属性（例如，它们位于何处以及如何连接）。随着数据存储与物理计算设备分离，用户将无处不在地访问、处理和计算他们的数据

Computer users store immense amounts of personal data and intellectual***property across a variety of storage media (SD cards, USB sticks, laptops,***attachments in e-mails, etc.), and these users are not given any guarantees***about storage security. Some techniques, like encryption, are used in some***places or to secure transmissions, but they are an aspect of what stores the***data and not a policy tied to the data.******There exists a variety of techniques for improving storage, such as encryption, secure***deletion, deniable storage, history independence, and storage virtualization.***Despite that, they are frequently not used together and none are widely used in***practice. While this is sub-optimal for some users, it completely fails the world's***more-extreme users working in hostile environments, such as military, journalists,***and political dissidents. This work will raise the minimum standard for storage security***by providing security as part of standard file systems.******The research program has two broad components. One focuses on improving the***security of portable flash-based storage to act as a first line of defense.***Flash memory is widely used but it has a characteristic nuance: data cannot be***overwritten. Instead new data is written out of place, and deletion can only***happen at a large granularity. This has significant implications on the***algorithms and file systems that store, read, and delete data. It also severely***complicates several security features that would normally be easily***provided. Building on a deep understanding of the challenges in designing flash***file systems, this work will design a next-generation flash file system with the***goals of harmonizing encryption, secure deletion, deniability, and other features***without a significant cost in the usability and performance of the resulting file***system.******The second component is developing usable techniques to allow users to specify***storage policy for data without having to specify the particular storage medium***to use. Currently, users put files on USB sticks to make them portable, or***e-mail it to themselves to access it on other computers. Users frequently make***ad hoc backups, and store data in multiple places without a clear understanding***of how, or even where, the data is stored. Current techniques people use to***safeguard their data are inconvenient, insecure, unreliable, or unusable. We will***create a Virtual Storage Device (VSD) to address these problems. The VSD will***be a router for data to and from storage endpoints, allowing users to focus on***the storage properties that they desire, such as security, speed, reliability, and***cost. The VSD will abstract the physical properties of storage media (e.g., where***they are located and how they are connected) from the policy and risk attributes***that are meaningful to the user. Users will access, work on, and compute with***their data ubiquitously as the data storage is separated from the physical***computation devices.**