Realizing Full-System Dynamic Information Flow Tracking via Relaxed Static Stability

信息流是计算机安全中的一个核心概念，然而如何在运行中的系统中标记信息并准确地跟踪信息在整个系统中的流动，仍然是一个悬而未决的问题。我们正在发展控制理论、信息论和系统的基本概念，用我们所谓的放松静态稳定性方法来解决这个问题。在运行中的系统中，当信息被用户剪切和粘贴或处理时，它以意想不到的方式流动。两个主要的挑战是处理依赖关系和控制依赖关系。过度标记这些依赖关系会导致整个系统很快被标记，而标记不足则意味着重要的信息流没有被跟踪。现代战斗机和隐形飞机的设计没有固有的稳定性，然后将先进的数字“电传飞行”系统纳入设计中，以创建一个可以实际飞行的稳定系统。通过应用这种相同的“放松静态稳定性”方法，我们正在设计一个精确的动态信息流跟踪系统，在过度标记和欠标记之间做出正确的权衡。这将使基于动态信息流跟踪的全新应用程序类别成为可能，范围从数字取证和恶意软件分析到数据来源。通过解决安全和隐私研究的基本需求，我们希望我们的工作对任何需要了解计算机信息流的领域都有影响。

Information flow is a central concept in computer security, yet it is still an open problem to tag information in a running system and track how the information flows throughout the system in an accurate manner. We are developing the fundamental concepts in control theory, information theory, and systems to solve this problem using what we call a relaxed static stability approach.In a running system, as information is cut-and-pasted by users or processed, it flows in unexpected ways. Two major challenges are address dependencies and control dependencies. Overtagging these dependencies causes the entire system to quickly become tagged, while undertagging them means that important flows of information are not tracked. Modern fighter jets and stealth aircraft are designed without inherent stability, then advanced digital "fly-by-wire" systems are incorporated into the design to create a stable system that can actually fly. By applying this same kind of "relaxed static stability" approach, we are designing an accurate dynamic information flow tracking system that makes the right tradeoffs between overtagging and undertagging. This will enable whole new classes of applications based on dynamic information flow tracking, ranging from digital forensics and malware analysis to data provenance. By addressing a fundamental need in security and privacy research, we expect our work to have impact in any field where the flow of information in a computer is important to understand.