TWC: Small: Communication under Adversarial Attacks in Complex Networks - Fundamental Limits and Secure Coding Strategies

当今世界高度依赖于通信系统的完整性，如互联网、WiFi或蜂窝网络。随着网络变得越来越普遍，它们越来越多地用于通信和存储关键和敏感数据，因此对可靠性和安全性提出了更严格的要求，即使在极端环境下，如部分停电，自然灾害，或者最重要的是，对抗性攻击，也必须保持可靠性和安全性。本研究旨在了解保护复杂的实际网络免受对抗性攻击的基本限制，以及如何通过最佳安全策略实现这些限制，从而弥合先进的理论研究和现实解决方案的开发之间的差距。此外，该项目能够对许多其他采用可靠网络通信的关键应用程序产生重大变革性影响，例如在医疗保健，环境监测，金融等领域，它还提供了一个平台，以创造更广泛的技术，社会，研究和教育影响，通过新建立的理论和实践推进信息技术及其对社会的好处，一个雄心勃勃的教育计划，并积极吸引学生从代表性不足的人口。具体来说，该项目侧重于方面（例如，分布式用户、异质性、延迟要求、由概率分布描述的对手的动作）在真实的网络系统中是重要的，但在当前文献中理解得很少，并且试图阐明每个这样的方面对容量和代码设计的影响。本研究旨在描述问题和解决方案的特征（例如，计算对抗攻击下的通信速率的难度，不同网络流中冗余之间的相互作用，以及非均匀对抗集），以及识别每个新场景中所需解决方案之间的共性。然后，这些共性被应用于描述一般对抗网络中安全性和性能之间的基本权衡。这里采用的技术是通过减少，这表明两个问题之间的关系，通过显示，任何解决方案的一个可以用来建立一个解决方案的其他。特别是，减少来自嘈杂的网络与对手选择的状态和相应的无噪声和无状态的版本，其容量更容易表征。此外，这些结果导致的分析性能保证所设计的安全编码策略，从而提供指导，具体的设计方法和容量界限仍然开放的情况下。

Today's world is highly dependent on the integrity of communication systems as the Internet, WiFi, or cellular networks. As networks become more pervasive, they are increasingly being used for communication and storage of critical as well as sensitive data and therefore impose more stringent demands on reliability and security, which must be maintained even under extreme settings such as partial power failures, natural disasters, or, most importantly, adversarial attacks. This research seeks to understand fundamental limits of protecting complex practical networks against adversarial attacks, and how these limits can be achieved by optimal secure strategies, thus bridging the gap between advanced theoretical research and the development of realistic solutions. Further, the project is able to provide a significant transformative impact on many other critical applications employing reliable networked communications, for example in the fields of healthcare, environmental monitoring, finance, etc. It also provides a platform for creating broader technological, societal, research, and educational impact as advancing information technology and its benefits to society through newly established theory and practice, an ambitious education plan, and actively engaging students from underrepresented demographics.Specifically, the project focuses on aspects (e.g., distributed users, heterogeneity, delay requirements, actions of adversaries described by probability distributions) important in real network systems but poorly understood in current literature, and seeks to elucidate the impact of each such aspect on capacity and code design. This research aims both to characterize features of the problems and solutions (e.g., hardness of computing the rate of communication under adversarial attacks, interaction between redundancy in different network flows, and non-uniform adversarial sets) that are new to the literature, as well as to identify commonalities between the solutions required in each new scenario. These commonalities are then applied to characterize the fundamental tradeoff between security and performance in general adversarial networks. The technique employed here is via reductions, which demonstrate the relationship between two problems by showing that any solution for one can be employed to build a solution for the other. In particular, reductions are derived between noisy networks with a state chosen by the adversary and their corresponding noiseless and stateless versions, for which capacity is much easier to characterize. Further, these results lead to analytical performance guarantees for the designed secure coding strategies, thus providing guidance on specific design approaches and for those cases where capacity bounds are still open.