Quantum communication networks are the trends toward multiple users' unconditional secure communication. Based on several passive optical devices, various types of fiber-based Quantum Key Distribution (QKD) networks have been proposed. However, it is still hard to accurately assess these networks. To find the optimal solution, a general assessment that would not involve detailed schemes is quite necessary. In this paper, we introduce an evaluation method and analyze optical-device-based QKD networks including two rational aspects: (i) network connectivity and network bandwidth which reflect the network's flexibility and performance in theory; (ii) network cost that brings pragmatic restriction on the network construction in practice. Applying this model, we compare five typical types of optical-device-based QKD networks. The explicit results demonstrate the above networks' characteristics and some valuable conclusions.
Quantum communication networks are the trends toward multiple users' unconditional secure communication. Based on several passive optical devices, various types of fiber-based Quantum Key Distribution (QKD) networks have been proposed. However, it is still hard to accurately assess these networks. To find the optimal solution, a general assessment that would not involve detailed schemes is quite necessary. In this paper, we introduce an evaluation method and analyze optical-device-based QKD networks including two rational aspects: (i) network connectivity and network bandwidth which reflect the network's flexibility and performance in theory; (ii) network cost that brings pragmatic restriction on the network construction in practice. Applying this model, we compare five typical types of optical-device-based QKD networks. The explicit results demonstrate the above networks' characteristics and some valuable conclusions.
Quantum Key Distribution (QKD) networks are the trends toward multiple users' unconditional secure communication. Based on several passive optical devices, such as beam splitter, optical switch or wavelength divided multiplexer, various types of fiber-based QKD networks have been proposed. However, it is still hard to accurately assess these networks. To find the optimal solution, a general assessment that would not involve detailed schemes is quite necessary. In this paper, we introduce an evaluation method and analyze optical-device-based QKD networks including two rational aspects: (i) network connectivity and network bandwidth which reflect the network's flexibility and performance in theory; (ii) network cost that brings pragmatic restriction on the network construction in practice. Applying this model, we compare five typical types of optical-device-based QKD networks. The explicit results demonstrate the above networks' characteristics and some valuable conclusions.
It is well known that optical access networks are able to provide high data rates over long distances and to a reasonable number of users. Security and privacy are always a challenge for public accessible network infrastructures. Especially in time-division multiplexing passive optical networks (TDM-PONs), in which the downstream signal is broadcasted to all users connected via the same wavelength channel in a shared fiber link, privacy can be a critical concern. Although encryption at the application layer can provide a high level of security, this can be achieved only if the encryption key distribution is perfectly save. On the other hand, encryption on the physical layer such as quantum cryptography or, more precisely, quantum key distribution (QKD) is a very promising approach to achieve secure communication. However, there remain several issues that have to be solved before the quantum cryptography reaches the maturity level needed for a cost effective implementation in practical networks. In this paper, we address quantum key distribution (QKD) over passive optical access networks, which is an enabling technology required to cost efficiently deploy practical quantum encrypted data communication in the access area. We study different methods to integrate QKD systems in conventional optical access networks and quantitatively evaluate their suitability for a potential implementation.
The increasing number of cyber threats and the approaching development of quantum computing demand a critical review of existing cryptographic approaches. The goal of this work is to evaluate the security and practicality of utilizing Quantum Key Distribution for secure communications. QKD utilizes the laws of quantum mechanics to provide a secure and unbreakable method for exchanging information. Protocols like BB84 are resistant to threatening attacks from both classical and quantum adversaries. The methodology utilizes simulated models and quantum communication toolkits to study critical characteristics such as key generation speed, QBER, latency and scalability. Performance of QKD is compared to that of classical schemes such as RSA-2048, ECC-256 and AES-256. Results reveal that although QKD provides unparalleled theoretical security, its deployment has notable obstacles such as intricate infrastructure, restrictions on distance and elevated latency. Our study reveals that optimizing the interplay between security and practicality in QKD deployment can yield a highly effective safeguard for next-generation communication networks.
Increasing incidents of cyber attacks and evolution of quantum computing poses challenges to secure existing information and communication technologies infrastructure. In recent years, quantum key distribution (QKD) is being extensively researched, and is widely accepted as a promising technology to realize secure networks. Optical fiber networks carry a huge amount of information, and are widely deployed around the world in the backbone terrestrial, submarine, metro, and access networks. Thus, instead of using separate dark fibers for quantum communication, integration of QKD with the existing classical optical networks has been proposed as a cost-efficient solution, however, this integration introduces new research challenges. In this paper, we do a comprehensive survey of the state-of-the-art QKD secured optical networks, which is going to shape communication networks in the coming decades. We elucidate the methods and protocols used in QKD secured optical networks, and describe the process of key establishment. Various methods proposed in the literature to address the networking challenges in QKD secured optical networks, specifically, routing, wavelength and time-slot allocation (RWTA), resiliency, trusted repeater node (TRN) placement, QKD for multicast service, and quantum key recycling are described and compared in detail. This survey begins with the introduction to QKD and its advantages over conventional encryption methods. Thereafter, an overview of QKD is given including quantum bits, basic QKD system, QKD schemes and protocol families along with the detailed description of QKD process based on the Bennett and Brassard-84 (BB84) protocol as it is the most widely used QKD protocol in the literature. QKD system are also prone to some specific types of attacks, hence, we describe the types of quantum hacking attacks on the QKD system along with the methods used to prevent them. Subsequently, the process of point-to-point mechanism of QKD over an optical fiber link is described in detail using the BB84 protocol. Different architectures of QKD secured optical networks are described next. Finally, major findings from this comprehensive survey are summarized with highlighting open issues and challenges in QKD secured optical networks.
Quantum Key Distribution (QKD) networks allow multiple users to generate and share secret quantum keys with unconditional security. Although many schemes of QKD networks have been presented, they are only concentrated on the system realization and physical implementations. For the complete practical quantum network, a succinct theoretic model that systematically describes the working processes from physical schemes to key process protocols, from network topology to key management, and from quantum communication to classical communication is still absent. One would hope that research and experience have shown that there are certain succinct model in the design of communication network. With demonstration of the different QKD links and the four primary types of quantum networks including probability multiplexing, wavelength multiplexing, time multiplexing and quantum multiplexing, we suggest a layer model for QKD networks which will be compatible with different implementations and protocols. We divide it into four main layers by their functional independency while defining each layer's services and responsibilities in detail, orderly named quantum links layer, quantum networks layer, quantum key distribution protocols process layer, and keys management layer. It will be helpful for the systematic design and construction of real QKD networks.
Abstract Passive Optical Networks (PON) are widely used to deliver fixed line communication due to their cost effectiveness and potential for high data transfer rates. However, due to the nature of their operation, every user on a PON system has access to every other user’s downstream data. Current progress in quantum computing means that the classical encryption algorithms currently used to secure communication data, including PON data, may not be sufficient in the future and so, for total information security another encryption solution, such as Quantum Key Distribution, must be found. This paper outlines the different variations of QKD on PON that have so far been proposed and summarises the current state of the art of experimental demonstrations of QKD on PON.