TWC: Medium: Leakage of Communications Signatures: Analysis of Eavesdropping Attacks and Proactive Countermeasures

随着社会继续依赖快速扩展的无线生态系统，我们面临着与用户隐私、数据机密性和关键系统可用性相关的严重威胁。这些威胁很大一部分归因于无线传输的广播性。使用商用无线电硬件，未经授权方可以很容易地窃听空中传输，并通过跟踪通信用户的下落和移动，并推断他们的关联、健康状态和偏好来侵犯通信用户的隐私。常见的(应用级)加密机制无法提供足够的安全性和保密性，因为它们使低级传输标识符对流量分析开放。本项目的重点是设计和评估保护隐私的通信方法，以减少由于窃听而导致的信息泄露。正在设计新的物理层混淆技术，该技术仔细地控制来自发射机和/或接收机的故意干扰，以防止在帧级别进行业务分析。这些技术的目标是使分组(包括其未加密的报头)无法被任何未经授权方破译。这些物理层技术通过流级别的流量标准化机制得到增强，其目标是隐藏复杂的网络和流量特征，如设备角色、路由路径等。还将调查长期监视系统的串通窃听者。该项目的成果预计将对依赖无线技术的各种关键系统的安全、隐私和可用性产生深远影响，这些系统包括交通和航空网络、移动计算平台、电子商务、关键国家基础设施、医疗系统等。

As society continues to depend on the rapidly expanding wireless ecosystem, we are challenged with serious threats related to user privacy, data confidentiality, and critical system availability. A significant portion of these threats is attributed to the broadcast nature of wireless transmissions. Using commodity radio hardware, unauthorized parties can easily eavesdrop on over-the-air transmissions and breach the privacy of communicating users by tracking their whereabouts and movements, and inferring their associations, health state, and preferences. Common (application-level) cryptographic mechanisms fail to provide adequate security and privacy, as they leave low-level transmission identifiers open to traffic analysis. This project focuses on designing and evaluating privacy-preserving communication methods for mitigating information leakage due to eavesdropping. Novel physical-layer obfuscation techniques that carefully control intentional interference from transmitters and/or receivers are being designed to prevent traffic analysis at the frame level. The goal of these techniques is to render packets (including their unencrypted headers) undecodable by any unauthorized party. These physical-layer techniques are augmented with traffic normalization mechanisms at the flow level, whose objective is to hide complex network and traffic features, such as device role, routing paths, etc. Colluding eavesdroppers who monitor the system for long periods of time are also being investigated. The outcomes of this project are expected to have profound impacts on the security, privacy, and usability of a wide range of critical systems that rely on wireless technologies, including transportation and aviation networks, mobile computing platforms, e-commerce, critical national infrastructures, medical systems, and others.