Collaborative Research: Communicating Confidential Information over Wireless Networks

本研究考虑了无线网络中的物理层安全问题。它通过考虑无线介质本身的安全性，作为传统安全方法的对立面，例如计算安全的密码系统。这项研究的一个重要动机是无线通信设备、技术和应用总体上的快速增长。无线网络的本质不仅暴露了恶意用户可以利用并严重危害网络的风险和漏洞，而且还暴露了与网络内终端有关的信息保密问题。尽管无线技术正变得越来越安全，但攻击者正变得越来越聪明，从安全角度来看，在终端可能受到攻击的大型分布式网络中，仅依赖密钥是不可持续的。这一过程的直接后果是需要在最基本的物理层级别解决安全问题，其中(无条件的)保密性可能体现在信息本身中，并且还适应通信介质和网络条件。此外，需要一种安全的密钥分发，该过程只能使用物理层技术在完全保密的情况下执行，即使从今以后依赖于传统的密码技术。本研究研究了在安全无线网络中，相对于通信信道相干时间的应用延迟要求如何体现在信令策略的选择和在规定安全级别下可实现的通信速率方面。此外，可能令人惊讶的是，适用于无线信道的实用的安全嵌套前向纠错码和安全自适应增量纠错策略的成功设计实际上是不存在的。因此，本研究将重点放在实际的编码方案设计上，作为必要的使能工具。

This research considers physical layer security in wireless networks. It serves as a counterpoint to traditional methods of security, such as computationally secure crypto-systems, by considering security in the wireless medium itself. An important motivator for this research is the rapid proliferation of wireless communication devices, technologies, and applications, in general. The very nature of wireless networks exposes not only the risks and vulnerabilities that a malicious user can exploit and severely compromise the network but also information confidentiality concerns with respect to the in-network terminals. Although wireless technologies are becoming more and more secure, attackers are becoming smarter, and sole reliance on cryptographic keys in large distributed networks, for example, where terminals can be compromised is unsustainable from the security perspective. A direct consequence of this process is the need to, additionally, tackle security at the very basic physical layer level where the (unconditional) secrecy may be embodied within the information itself, and, also, adapted to the communication medium and network conditions. Furthermore, there is a need for a secure key distribution, a process which can be performed in perfect secrecy only using physical layer techniques, even when, henceforth, relying on conventional cryptographic techniques.This research studies how, in secure wireless networks, the application delay requirement relative to the communication channel coherence time aspects the selection of signaling strategies and the achievable communication rates at a prescribed security level. In addition, perhaps surprisingly,successful design of practical secure nested forward error correction codes and secure adaptive incremental error correction strategies applicable to wireless channels is virtually non-existent. Hence, this research focuses on practical coding-scheme designs as essential enabling tools.