TWC: Small: Time Advantage-based Key Establishment Protocols for Low-cost Wireless Networked Systems

信息保障的本质在于合法通信各方建立并保持对其对手的优势的能力。大多数情况下，这种优势以密钥的形式存在。与标准密钥建立协议相关的高成本激发了最近非常规协议的激增，这些协议从物理特征（对手可能拥有比合法接收者更差的信道）或相关的随机性来源（两个设备一起震动时的加速度计读数）中获得合法各方的优势。主要的缺点是设备通常不知道它们彼此之间的物理位置。因此，需要人为干预（通常被认为是安全协议中最薄弱的环节）来通知他们已经实现了安全环境。即使这些设备自动测量他们的相对距离，它们也无法知道他们是在家里，还是在拥挤的公交车上。此外，无论是自动的还是人为发起的，此类密钥交换都依赖于底层身份验证协议的安全性。这个项目的目标是探索一个完全被忽视的关键建立资源：时间。该项目研究了在安全环境中花费的长时间和不间断的时间间隔如何用于创建或补充低成本无线消费电子产品的安全密钥建立协议。派生的协议必须(1)独立（不依赖于其他协议的安全性，如身份验证）和(2)自动（不需要人为干预）。建议的研究将适用于广泛的信息保障应用，并有可能激发大量的相关研究，并为本科生和研究生（特别是少数民族和女性）创造参与前沿研究的机会。为了避免对人类交互或认证机制的依赖，一个研究方向是实现一个反直觉的范式：合法的一方创建一个谜题并输出时间限制的线索，而其他合法的一方收集线索，直到他们能够解决这个谜题并将其解决方案加工成一个密钥。这个想法是基于随着时间以指数速率泄露信息的密码。因此，需要针对密钥信息泄漏的度量来量化合法各方的可用性和来自攻击者的安全性。该项目同时包括三个主要任务：(a)在基于谜题的范式下构建用于评估基于时间的密钥建立协议安全性的正式数学框架，并研究适合于基于时间的安全性的新范式；(b)针对低成本无线设备（可能既没有客观的时间概念，也没有计算资源来进行优势提炼、信息协调或隐私放大）的此类协议的设计和评估；(c)在物理无线试验台上实施所得解决方案。

The essence of information assurance resides in the ability of the legitimate communication parties to establish and maintain an advantage over their adversary. Most often, such an advantage is in the form of a secret key. The high costs associated with standard key establishment protocols motivate the recent surge of less conventional protocols, which derive the legitimate parties' advantage from physical features (the adversary may have a worse channel than the legitimate receiver) or from correlated sources of randomness (accelerometer readings when two devices are shaken together). The main drawback is that the devices will usually not be aware of their physical location relative to each-other. Therefore, human intervention (generally recognized as the weakest link in security protocols) is required to inform them that a secure environment has been realized. Even if the devices automatically measure their relative distance, they cannot know whether they're at home, or in a crowded bus. Moreover, whether automatic or human-initiated, such key exchanges rely on the security of an underlying authentication protocol. The goal of this project is to explore an entirely overlooked resource for key establishment: Time. The project investigates how the long and uninterrupted time intervals spent in secure environments can be used to create or complement secure key-establishment protocols for low-cost wireless consumer electronics. The derived protocols have to (1) stand alone (not rely on the security of other protocols, like authentication) and (2) be automatic (not require human intervention). The proposed research will be applicable to a broad spectrum of information-assurance applications, and has the potential to inspire an abundance of related research, and create opportunities for both undergraduate and graduate students (in particular minority and female) to participate in the cutting-edge research.To avoid the reliance on human interaction or authentication mechanisms, one research direction is to implement a counter-intuitive paradigm: one of the legitimate parties creates a puzzle and outputs time-throttled clues, while the other legitimate parties gather clues until they are able to solve the puzzle and process its solution into a secret key. The idea is based around ciphers that leak information at an exponential rate over time. Therefore, metrics for key-information leakage are needed to quantify both the availability at the legitimate parties, and the security from an adversary. The project consists of three major simultaneous tasks: (a) the construction of a formal mathematical framework for evaluating the security of time-based key-establishment protocols, under the puzzle-based paradigm, and the investigation of new paradigms fit for time-based security; (b) the design and evaluation of such protocols for low-cost wireless devices (that may have neither an objective notion of time, nor the computational resources to engage in advantage distillation, information reconciliation or privacy amplification); (c) implementation of the resulted solutions on a physical wireless testbed.