CIF: Small: Alignment for Secrecy: One-Time-Pads in the Air without Keys

在当今的通信网络中，大多数数据通过无线链路流动，这特别容易受到窃听攻击。虽然目前可用的加密算法提供了有用的保护，防止计算有限的窃听者，不断增加的计算能力的对手需要技术，提供更强的形式的安全保证。信息理论物理层安全提供了无条件的安全保证，即使对计算上无限的对手也有效。本研究的目标是提高信息理论物理层安全性，以解决用户行为不当、用户利益冲突、缺乏完整的网络状态信息等实际问题;在信息理论物理层安全性应用于多用户无线信道时，对准作为实现网络的最大可能安全自由度的强大工具而出现。出于安全目的的最佳对齐可以被解释为一种空中一次性密码本通信的形式，不需要显式交换密钥;安全性是从物理信道中的随机性和用户合作的意愿中引导的。本研究的目标是开发技术，使这种安全的对齐方案更强大的用户的不当行为和缺乏信道状态信息;更实用的连接到极化编码开发显式代码;和更广泛地适用于现代无线网络与多天线节点。具体而言，本研究调查的情况下，1）偏离用户谁不遵循商定的最佳协议; 2）打击助手和自私的用户有冲突的利益; 3）矢量信道所产生的使用多个天线和相关的信道状态信息的问题;和4）显式码设计使用极化码和相关的极化对齐和信号对齐。

In today's communication networks, most data flow through wireless links which are particularly vulnerable to eavesdropping attacks. While currently available cryptographic algorithms provide useful protection against computationally limited eavesdroppers, the ever-increasing computational power of adversaries necessitates techniques that provide stronger forms of security guarantees. Information-theoretic physical layer security provides unconditional security guarantees that are valid even against computationally unlimited adversaries. The goal of this research is to advance information-theoretic physical layer security to address practical issues arising from user misbehavior, conflicting user interests, lack of complete network state information; and to devise practically implementable codes.In the application of information-theoretic physical layer security to multi-user wireless channels, alignment emerges as a powerful tool to achieve the maximum possible secure degrees of freedom for the network. Optimal alignment for the purposes of security may be interpreted as a form of one-time-pad communication in the air with no need for explicit exchange of keys; security is bootstrapped from the randomness in the physical channel and from the willingness of the users to cooperate. The goal of this research is to develop techniques to make such secure alignment schemes more robust to user misbehavior and to the lack of channel state information; more practical by making connections to polar coding to develop explicit codes; and more widely applicable to modern wireless networks with multi-antenna nodes. Specifically, this research investigates the cases of 1) deviating users who do not follow agreed-upon optimum protocols; 2) combating helpers and selfish users who have conflicting interests; 3) vector channels arising from use of multiple antennas and the associated channel state information issues; and 4) explicit code design using polar codes and relating polar alignment and signal alignment.