Collaborative Research: CT-ISG: Secure Capacity of Wireless Networks

合作研究：CT-ISG：无线网络的安全容量过去十年见证了无线通信和网络应用的惊人增长。越来越多的用户仅仅依靠他们的无线通信和计算设备来传递敏感信息。保护无线传输信息的安全性正变得越来越具有挑战性，但也是必不可少的。这个重要的问题目前是在协议层次结构的较高层处理的，但是在物理层处理它的需求迫在眉睫，因为许多加密算法的安全性很难评估，并且在过去造成了失望。此外，人们对包括传感器节点和RF-ID标签在内的低复杂度发射器的大型网络越来越感兴趣，这些网络可能没有空间容纳复杂和计算密集型的加密算法。迄今为止，低层协议层无线通信和网络的主要设计目标是通过有效地应对无线信道的挑战和共享有限的无线资源，为尽可能多的用户提供高数据速率、可靠的通信。以容量最大化为导向的研究对信息传输的安全要求缺乏认识。同时，传输信息的安全性是在协议层次的上层处理的，与底层网络的容量无关。本项目汇集了无线网络设计中两个最重要的问题，即信息容量和信息安全，揭示了两者之间的紧密耦合，旨在确定高容量和可证明安全的无线网络的设计原则。本课题采用信息论的方法，为无线网络的信息安全和信息可靠性提供保障。该研究包括开发一个全面的无线网络设计框架，旨在为所有用户实现高容量和安全传输。考虑到各种恶意实体的存在以及这些实体能够损害网络的各种级别，研究人员确定了以下基本研究方向：(i)建立无线网络基本构建块的保密能力，即在存在智能窃听者的情况下可靠信息传输的最大速率；寻找合法的系统实体（即发送者和接收者）能够应对物理层安全威胁的方法；（ii）确定友好节点之间的用户合作与中继信息的安全性和保密性之间的基本权衡；（iii）在存在安全威胁的情况下，重新审视无线传输信道状态信息（CSI）的概念；确定这种被广泛接受的提高能力的概念可能产生安全漏洞的条件，并开发处理这种情况的方法；（iv）引入保障网络安全的概念，利用多天线（MIMO链路）所带来的可用通信信道的自由度；(v)确定物理层对媒介接入层和网络层的影响，并制定安全的跨层解决方案。该项目的结果将有助于确定各种无线网络的容量与安全性的基本设计权衡，并将为实现安全容量限制的未来无线通信系统提供设计原则。该项目是宾夕法尼亚州立大学PI和马里兰大学PI的合作成果。

Collaborative Research: CT-ISG: Secure Capacity of Wireless NetworksThe last decade has witnessed an amazing growth in wireless communications and networking applications. More and more subscribers are relying solely on their wireless communication and computing devices for communicating sensitive information. Preserving the security of wirelessly transmitted information is becoming ever more challenging, yet essential. This important issue is currently dealt with at the higher layers of the protocol hierarchies, yet the need to deal with it in physical layer is imminent as the security of many cryptographic algorithms is hard to evaluate and has caused disappointment in the past. In addition, there is rising interest in large networks of low-complexity transmitters including sensor nodes and RF-ID tags that may not have room for complicated and computationally intensive cryptographic algorithms.The main design goal up to date, for wireless communications and networking at the lower protocol layers, has been to provide high data rate, reliable communication to as many users as possible, by efficiently dealing with the challenges of the radio channel and sharing limited wireless resources. Capacity maximization oriented research has been agnostic to the security requirements of information transmitted. At the same time, security of the information transmitted has been dealt with at the upper layers of the protocol hierarchy, and has been agnostic to the capacity of the underlying network. This project brings together the two most important issues in wireless network design, i.e., information capacity and information security, exposing the tight coupling between the two, and aims to identify design principles for high-capacity and provably-secure wireless networks.This project takes an information theoretic approach to provide guarantees on information security and information reliability for wireless networks. The research includes the development of a comprehensive wireless network design framework that aims at achieving high capacity and secure transmission for all users. Accounting for the existence of a variety of malicious entities and a variety of levels at which these entities are capable to harm the network, the investigators identify the following fundamental research directions: (i) establishing the secrecy capacity of fundamental building blocks of wireless networks, i.e., the maximum rate of reliable information transmission in the presence of intelligent eavesdroppers; finding ways in which the legitimate system entities, i.e., transmitters and receivers, can cope with the security threats at the physical layer; (ii) identifying the fundamental tradeoffs between user cooperation between friendly nodes and the security and the confidentiality of relayed information; (iii) revisiting the notion of wirelessly transmitting channel state information (CSI) in the presence of security threats; identifying conditions under which this well-accepted notion to improve capacity may create security vulnerabilities, and developing methods to deal with this; (iv) introducing the notion of securing the network by utilizing the degrees of freedom in the communication channel available as a result of employing multiple antennas (MIMO links); (v) identifying the impact of the physical layer on the medium access and networking layers and developing secure cross-layer solutions.The results of this project will help identify fundamental design trade-offs for capacity versus security for a variety of wireless networks, and will provide design principles for future wireless communication systems achieving the secure capacity limits. The project is a collaborative effort between the PI at Penn State and the PI at University of Maryland.