Principles of Physical Layer Security in Multiuser Wireless Networks: A Survey

This paper provides a comprehensive review of the domain of physical layer security in multiuser wireless networks. The essential premise of physical-layer security is to enable the exchange of confidential messages over a wireless medium in the presence of unauthorized eavesdroppers without relying on higher-layer encryption. This can be achieved primarily in two ways: without the need for a secret key by intelligently designing transmit coding strategies, or by exploiting the wireless communication medium to develop secret keys over public channels. The survey begins with an overview of the foundations dating back to the pioneering work of Shannon and Wyner on information-theoretic security. We then describe the evolution of secure transmission strategies from point-to-point channels to multiple-antenna systems, followed by generalizations to multiuser broadcast, multiple-access, interference, and relay networks. Secret-key generation and establishment protocols based on physical layer mechanisms are subsequently covered. Approaches for secrecy based on channel coding design are then examined, along with a description of inter-disciplinary approaches based on game theory and stochastic geometry. The associated problem of physical-layer message authentication is also introduced briefly. The survey concludes with observations on potential research directions in this area.Comment: 23 pages, 10 figures, 303 refs. arXiv admin note: text overlap with arXiv:1303.1609 by other authors. IEEE Communications Surveys and Tutorials, 201

Security of Ubiquitous Computing Systems

The chapters in this open access book arise out of the EU Cost Action project Cryptacus, the objective of which was to improve and adapt existent cryptanalysis methodologies and tools to the ubiquitous computing framework. The cryptanalysis implemented lies along four axes: cryptographic models, cryptanalysis of building blocks, hardware and software security engineering, and security assessment of real-world systems. The authors are top-class researchers in security and cryptography, and the contributions are of value to researchers and practitioners in these domains. This book is open access under a CC BY license

Security of Ubiquitous Computing Systems

The chapters in this open access book arise out of the EU Cost Action project Cryptacus, the objective of which was to improve and adapt existent cryptanalysis methodologies and tools to the ubiquitous computing framework. The cryptanalysis implemented lies along four axes: cryptographic models, cryptanalysis of building blocks, hardware and software security engineering, and security assessment of real-world systems. The authors are top-class researchers in security and cryptography, and the contributions are of value to researchers and practitioners in these domains. This book is open access under a CC BY license

Quantum information in security protocols

Information security deals with the protection of our digital infrastructure. Achieving meaningful real-world security requires powerful cryptographic models that can give strong security guarantees and it requires accuracy of the model. Substantial engineering effort is required to ensure that a deployment meets the requirements imposed by the model. Quantum information impacts the field of security in two major ways. First, it allows more efficient cryptanalysis of currently widely deployed systems. New "post-quantum" cryptographic algorithms are designed to be secure against quantum attacks, but do not require quantum technology to be implemented. Since post-quantum algorithms have different properties, substantial effort is required to integrate these in the existing infrastructure. Second, quantum cryptography leverages quantum-mechanical properties to build new cryptographic systems with potential advantages, however these require a more substantial overhaul of the infrastructure. In this thesis I highlight the necessity of both the mathematical rigour and the engineering efforts that go into security protocols in the context of quantum information. This is done in three different contexts. First, I analyze the impact of key exhaustion attacks against quantum key distribution, showing that they can lead to substantial loss of security. I also provide two mitigations that thwart such key exhaustion attacks by computationally bounded adversaries, without compromising the information theoretically secure properties of the protocol output. I give various security considerations for secure implementation of the mitigations. Second, I consider how quantum adversaries can successfully attack quantum distance bounding protocols that had previously been claimed to be secure by informal reasoning. This highlights the need for mathematical rigour in the analysis of quantum adversaries. Third, I propose a post-quantum replacement for the socialist millionaire protocol in secure messaging. The protocol prevents some of the usability problems that have been observed in other key authentication ceremonies. The post-quantum replacement utilizes techniques from private set intersection to build a protocol from primitives that have seen much scrutiny from the cryptographic community

A control theoretic approach for security of cyber-physical systems

In this dissertation, several novel defense methodologies for cyber-physical systems have been proposed. First, a special type of cyber-physical system, the RFID system, is considered for which a lightweight mutual authentication and ownership management protocol is proposed in order to protect the data confidentiality and integrity. Then considering the fact that the protection of the data confidentiality and integrity is insufficient to guarantee the security in cyber-physical systems, we turn to the development of a general framework for developing security schemes for cyber-physical systems wherein the cyber system states affect the physical system and vice versa. After that, we apply this general framework by selecting the traffic flow as the cyber system state and a novel attack detection scheme that is capable of capturing the abnormality in the traffic flow in those communication links due to a class of attacks has been proposed. On the other hand, an attack detection scheme that is capable of detecting both sensor and actuator attacks is proposed for the physical system in the presence of network induced delays and packet losses. Next, an attack detection scheme is proposed when the network parameters are unknown by using an optimal Q-learning approach. Finally, this attack detection and accommodation scheme has been further extended to the case where the network is modeled as a nonlinear system with unknown system dynamics --Abstract, page iv

Proof of Proximity of Knowledge

Public-key distance bounding schemes are needed to defeat relay attacks in payment systems. So far, only two such schemes exist, but fail to fully protect against malicious provers. In this paper, we solve this problem. We provide a full formalism to define the proof of proximity of knowledge (PoPoK). Protocols should succeed if and only if a prover holding a secret is within the proximity of the verifier. Like proofs of knowledge, these protocols must satisfy completeness, soundness (protection for the honest verifier), and security (protection for the honest prover). We construct ProProx, the very first fully secure PoPoK

Sound Proof of Proximity of Knowledge

Public-key distance bounding schemes are needed to defeat relay attacks in payment systems. So far, only five such schemes exist, but fail to fully protect against malicious provers. In this paper, we solve this problem. We provide a full formalism to define the proof of proximity of knowledge (PoPoK). Protocols should succeed if and only if a prover holding a secret is within the proximity of the verifier. Like proofs of knowledge, these protocols must satisfy completeness, soundness (protection for the honest verifier), and security (protection for the honest prover). We construct ProProx, the very first sound PoPoK