The growth of data-driven technologies, 5G, and the Internet place enormous pressure on underlying information infrastructure. There exist numerous proposals on how to deal with the possible capacity crunch. However, the security of both optical and wireless networks lags behind reliable and spectrally efficient transmission. Significant achievements have been made recently in the quantum computing arena. Because most conventional cryptography systems rely on computational security, which guarantees the security against an efficient eavesdropper for a limited time, with the advancement in quantum computing this security can be compromised. To solve these problems, various schemes providing perfect/unconditional security have been proposed including physical-layer security (PLS), quantum key distribution (QKD), and post-quantum cryptography. Unfortunately, it is still not clear how to integrate those different proposals with higher level cryptography schemes. So the purpose of the Special Issue entitled “Physical-Layer Security, Quantum Key Distribution and Post-quantum Cryptography” was to integrate these various approaches and enable the next generation of cryptography systems whose security cannot be broken by quantum computers. This book represents the reprint of the papers accepted for publication in the Special Issue.
The growth of data-driven technologies, 5G, and the Internet place enormous pressure on underlying information infrastructure. There exist numerous proposals on how to deal with the possible capacity crunch. However, the security of both optical and wireless networks lags behind reliable and spectrally efficient transmission. Significant achievements have been made recently in the quantum computing arena. Because most conventional cryptography systems rely on computational security, which guarantees the security against an efficient eavesdropper for a limited time, with the advancement in quantum computing this security can be compromised. To solve these problems, various schemes providing perfect/unconditional security have been proposed including physical-layer security (PLS), quantum key distribution (QKD), and post-quantum cryptography. Unfortunately, it is still not clear how to integrate those different proposals with higher level cryptography schemes. So the purpose of the Special Issue entitled “Physical-Layer Security, Quantum Key Distribution and Post-quantum Cryptography” was to integrate these various approaches and enable the next generation of cryptography systems whose security cannot be broken by quantum computers. This book represents the reprint of the papers accepted for publication in the Special Issue.
As digital communication continues to expand across critical infrastructures, ensuring data security has become more challenging in the face of advancing computational capabilities, especially with the anticipated rise of quantum computers. Quantum Key Distribution (QKD) presents a revolutionary approach to secure communications by leveraging the fundamental principles of quantum mechanics, such as superposition and entanglement, to enable the secure exchange of cryptographic keys. Unlike classical encryption methods that rely on computational complexity, QKD ensures unconditional security, as any attempt to intercept the key disturbs the quantum state, revealing the presence of eavesdroppers. This paper explores the current developments in QKD protocols, including BB84 and E91, as well as practical challenges in implementation, such as distance limitations and hardware requirements. Furthermore, it discusses recent advancements in satellite-based QKD, integrated photonics, and quantum networks, highlighting their potential to reshape the landscape of secure global communication. The integration of QKD into future communication infrastructure is positioned to be a cornerstone of post-quantum cryptography, making it a vital technology in the era of quantum computing.
Recent advances in quantum computing and quantum information theory represent a severe threat to the current state of the art of data protection. In this context, new quantum-safe techniques have emerged in recent decades, which fall into post-quantum and unconditionally secure cryptographic schemes. The firsts rely on computational problems supposed to be hard also for quantum computers. In contrast, the seconds do not depend on the difficulty of a computational problem and are therefore immune to quantum power. In particular, unconditionally secure techniques include Quantum Key Distribution (QKD) protocols for transmitting secret keys thanks to the quantum properties of light. In this work, we discuss QKD networks and post-quantum algorithms, considering their opportunities and limitations and showing that reconciliation between these two directions of cryptography is feasible and necessary for the quantum era.This work is part of the activities of the PON project “Development of quantum systems and technologies for IT security in communication networks” (QUANCOM) which aims to the realization of a metropolitan quantum communication network through the collaboration between universities, research centers and companies operating in the communication market area.
Quantum computing is a rapidly developing field with the potential to revolutionize many industries. However, it also poses a serious threat to the security of future networks as current communications rely on encryption to protect data from unauthorized access, which could be broken by quantum computers in the future. This means that they could be used to attack future networks like Beyond 5G (B5G) and Sixth Generation (6G) which are expected to be much more widely used than previous generations of networks. There are a number of things that can be done to mitigate the quantum threat to future networks. One approach is to develop new encryption algorithms, Post-Quantum Cryptography (PQC), that are resistant to quantum computers. Another approach is to use Quantum Key Distribution (QKD) to create secure keys that cannot be broken by quantum computers. This work examines the current state of quantum and post-quantum cryptography and their applications in upcoming generations of wireless networks such as 6G, and the challenges that might arise for their implementation. Additionally, a new isogeny-based post-quantum cryptographic scheme is presented. This paper aims to advance and contribute to the research and development of quantum security in future networks.
Every attempt to access to the Internet through a Web browser, email sent, VPN connection, VoIP call, instant message or other use of telecommunications systems involves cryptographic techniques. The most commonly applied technique is asymmetric cryptography, which is generally executed in the background without the user even being aware. It establishes a cryptographic code based on the computational complexity of mathematical problems. However, this type of cryptography, which is widely used in today’s telecommunications systems, is under threat as electronics and computing rapidly develop. The development of fifth-generation cellular networks (5G) is gaining momentum, and given its wide field of application, security requires special attention. This is especially true faced with the development of quantum computers. One solution to this security challenge is to use more advanced techniques to establish cryptographic keys that are not susceptible to attack. An essential part of quantum cryptography, Quantum Key Distribution (QKD) uses the principles of quantum physics to establish and distribute symmetric cryptographic keys between two geographically distant users. QKD establishes information-theoretically secure cryptographic keys that are resistant to eavesdropping when they are created. In this paper, we survey the security challenges and approaches in 5G networks concerning network protocols, interfaces and management organizations. We begin by examining the fundamentals of QKD and discuss the creation of QKD networks and their applications. We then outline QKD network architecture and its components and standards, following with a summary of QKD and post-quantum key distribution techniques and approaches for its integration into existing security frameworks such as VPNs (IPsec and MACsec). We also discuss the requirements, architecture and methods for implementing the FPGA-based encryptors needed to execute cryptographic algorithms with security keys. We discuss the performance and technologies of post-quantum cryptography, and finally, examine reported 5G demonstrations which have used quantum technologies, highlighting future research directions.
To ensure confidentiality, today's communications are encrypted under the notion of computational security, using hard mathematical problems to build ciphers that apparently cannot be cracked in a useful time. However, as these constructions are not agnostic to technological advances, some of these problems may be solved efficiently with future technologies, e.g. quantum computing. In wireless networks, physical layer security emerges as a post-quantum security solution that promises to mitigate these threats. This concept of secrecy exploits the physical properties of the wireless channel to encode information so that a certain degree of statistical independence between the message and the cyphertext is observed by the eavesdropper. This notion of secrecy allows building cryptosystems that are agnostic to the computing capabilities of the attacker, being widely accepted as one of the strongest notions of secrecy created so far. The objective of this chapter is to overview the concept of physical layer security and understand how its integration could be done in future wireless networks. For that purpose, the information-theoretical framework grounding the concept is introduced, and some basic design approaches are presented. These include PHY key generation methods, secure beamforming techniques, and cooperative jamming constructions. The mechanisms to enable the integration of these technologies in future 5G and beyond networks are discussed last.
Quantum technology, and especially quantum computing, is advancing rapidly. Our every-day secure communication infrastructure relies heavily on public key cryptography; unfortunately, many public key schemes are in fact insecure against quantum algorithms. Furthermore, adversaries who, today, capture information encrypted using classical key distribution systems, can wait and, as soon as quantum computers of sufficient power become available, they may decipher all previously captured information. While some new “post-quantum” public key systems are assumed to be secure against quantum computers, this is only an assumption and, even if the assumption remains valid, still results in systems that are less efficient for end-users than the more commonly used public key systems employed today. While the advent of quantum technology may seem detrimental to security, in fact, one may harness the power of quantum through quantum key distribution (QKD) for stronger security guarantees. Such QKD protocols allow two (or more) parties to establish a shared secret key, secure against an all-powerful adversary. Perhaps surprising is that QKD technology is already here both experimentally and commercially. This tutorial serves as an introduction to basic QKD along with QKD technology from a practical perspective. Quantum communication is a highly interdisciplinary field of research and one of the goals of this article is to introduce a larger set of researchers and practitioners to its study in the hopes of furthering its progress and eventual wide-scale adoption.