Presents the theoretical foundations, practical implementation, challenges and benefits of physical-layer security, a groundbreaking new model for secure communication.
This complete guide to physical-layer security presents the theoretical foundations, practical implementation, challenges and benefits of a groundbreaking new model for secure communication. Using a bottom-up approach from the link level all the way to end-to-end architectures, it provides essential practical tools that enable graduate students, industry professionals and researchers to build more secure systems by exploiting the noise inherent to communications channels. The book begins with a self-contained explanation of the information-theoretic limits of secure communications at the physical layer. It then goes on to develop practical coding schemes, building on the theoretical insights and enabling readers to understand the challenges and opportunities related to the design of physical layer security schemes. Finally, applications to multi-user communications and network coding are also included.
There has recently been significant interest in applying the principles of information-theoretical security and signal processing to secure physical layer systems. Although the community has made progress in understanding how the physical layer can support confidentiality and authentication, it is important to realize that there are many important issues that must be addressed if physical layer security is ever to be adopted by real and practical security systems. In this article, I briefly review several different flavors of physical layer security (at least for wireless systems), and then identify aspects (a.k.a. weaknesses) where the foundation for physical layer security needs to be strengthened. I then highlight that the opportunities for applying physical layer security to real systems will be quite rich if the community can overcome these challenges. In the course of the article, I note new directions for the community to investigate, with the objective of keeping physical layer security research targeted at having a practical impact on real systems.
The ongoing paradigm shift from classical centralized wireless technologies toward distributed large-scale networks such as the Internet of Things has introduced new security challenges that cannot be fully handled via traditional cryptographic means. In emerging wireless environments, devices have limited capabilities and are not controlled by a central control center; thus, the implementation of computationally expensive cryptographic techniques can be challenging. Motivated by this paradigm shift, substantial recent research has been investigating the use of the physical layer as a means to develop low-complexity and effective wireless security mechanisms. Such techniques are grouped under the umbrella of physical layer security. These techniques range from information-theoretic security, which exploits channel advantages to thwart eavesdropping, to physical layer fi ngerprinting techniques that exploit physical layer features for device identifi cation. In this context, providing state-of-the-art tutorials on the various approaches to physical layer security is of considerable interest. This Feature Topic gathers together tutorial-style and survey articles that provide an in-depth overview of the broad spectrum of security opportunities brought forward by physical layer security.
The ongoing paradigm shift from classical centralized wireless technologies toward distributed large-scale networks such as the Internet of Things has introduced new security challenges that cannot be fully handled via traditional cryptgraphic means. In such emerging wireless environments, devices have limited capabilities and are not controlled by a central control center; thus, the implementation of computationally expensive cryptographic techniques can be challenging. Motivated by these considerations, substantial recent research has been investigating the use of the physical layer as a means to develop low-complexity and effective wireless security mechanisms. Such techniques are grouped under the umbrella ofphysical layer security. These techniques range from information-theoretic security, which exploits channel advantages to thwart eavesdropping, to physical layer fingerprinting techniques that exploit physical layer features for device identification. In this context, providing state-of-the-art tutorials on the various approaches to physical layer security is of considerable interest. This Feature Topic gathers together such tutorial-style and overview articles that provide an in-depth overview of the broad spectrum of security opportunities brought forward by physical layer security.
In this work, we consider the pros and cons of using various layers of keyless coding to achieve secure and reliable communication over the Gaussian wiretap channel. We define a new approach to information theoretic security, called practical secrecy and the secrecy benefit, to be used over real-world channels and finite blocklength instantiations of coding layers, and use this new approach to show the fundamental reliability and security implications of several coding mechanisms that have traditionally been used for physical-layer security. We perform a systematic/structured analysis of the effect of error-control coding, scrambling, interleaving, and coset coding, as coding layers of a secrecy system. Using this new approach, scrambling and interleaving are shown to be of no effect in increasing information theoretic security, even when measuring the effect at the output of the eavesdropper's decoder. Error control coding is shown to present a trade-off between secrecy and reliability that is dictated by the chosen code and the signal-to-noise ratios at the legitimate and eavesdropping receivers. Finally, the benefits of secrecy coding are highlighted, and it is shown how one can shape the secrecy benefit according to system specifications using combinations of different layers of coding to achieve both reliable and secure throughput.