NSFSaTC-BSF: TWC: Small: Practical Plausibly Deniable Encryption through Low-Level Storage Device Behavior

貌似可否认的加密是一种隐藏设备上给定数据的能力，无论是否存在解密能力，甚至数据是否存在。合理的推诿是保护用户失去物理控制的设备上的数据的强大属性，例如保护消费者免受因放错位置的设备而意外泄露的大量私人数据。任何携带敏感数据进行国际旅行的人，包括人权工作者、外交官、军事人员，甚至商务旅行者，都特别关注这个问题。该项目利用闪存和其他紧急持久存储器的低级特性，以合理的可否认性隐藏数据，提高性能和容量。这个项目研究了一个独特的机会，利用闪存的底层电学特性实现看似不可否认的加密。flash的一个很有前途的特性是同一个硬件单元可以以多种方式对数据进行编码，并且可以动态地调整编码。该项目将这种编码机制与数据隐藏集成在一起：只要编码遵循预期的电压分布，攻击者就无法识别精确的编码技术或编码的数据量。该项目还研究了固件级技术来管理隐藏数据；将这些技术扩展到新兴的持久记忆，如相变记忆；并增强了广泛使用的flash模拟器。本项目为低级flash编程开发新颖的教材。

Plausibly deniable encryption is the ability to hide that given data is on a device, whether the ability exists to decrypt it, or even that the data exists. Plausible deniability is a powerful property to protect data on devices the user has lost physical control over, such as protecting consumers from accidental mass disclosures of private data through misplaced devices. This issue is of particular concern for anyone who travels internationally with sensitive data, including human rights workers, diplomats, military personnel, or even business travelers. This project leverages low-level characteristics of flash and other emergent persistent memories to hide data with plausible deniability, improving performance and capacity over the state of the art. This project investigates a unique opportunity to implement plausibly deniable encryption using the underlying electrical properties of flash memory. The promising property of flash is that the same hardware cell can encode data in multiple ways, and adjust the encoding dynamically. This project integrates this encoding mechanism with data hiding: as long as the encoding follows an expected voltage distribution, an adversary cannot discern the precise encoding technique or how much data is encoded. This project also investigates firmware-level techniques to manage hidden data; extends these techniques to emerging persistent memories, such as phase change memory; and augments widely-used flash simulators. This project develops novel teaching materials for low-level flash programming.