Despite the challenges, several researchers from academia, business, and government are conducting extensive research and development on quantum key distribution (QKD), a symmetric secret key that secures the secrecy of quantum communications. A QKD network is made up of two or more QKD nodes connected by optical fiber or open space. To ensure long-term security and forward secrecy, secret keys are negotiated between any two QKD nodes before being given to many users in multiple locations. In actuality, most QKD algorithms communicate across two separate channels. There are two channels: classical for QKD and quantum for quantum communication. This work offers a single-channel QKD technique for both traditional and quantum communication. To our knowledge, there is no single channel source validated QKD protocol in the literature. This study provides the foundation for the verified source of QKD.
Despite the challenges, several researchers from academia, business, and government are conducting extensive research and development on quantum key distribution (QKD), a symmetric secret key that secures the secrecy of quantum communications. A QKD network is made up of two or more QKD nodes connected by optical fiber or open space. To ensure long-term security and forward secrecy, secret keys are negotiated between any two QKD nodes before being given to many users in multiple locations. In actuality, most QKD algorithms communicate across two separate channels. There are two channels: classical for QKD and quantum for quantum communication. This work offers a single-channel QKD technique for both traditional and quantum communication. To our knowledge, there is no single channel source validated QKD protocol in the literature. This study provides the foundation for the verified source of QKD.
Quantum key distribution (QKD) constitutes a symmetric secret key negotiation protocol capable of maintaining information-theoretic security. Given the recent advances in QKD networks, they have evolved from academic research to some preliminary applications. A QKD network consists of two or more QKD nodes interconnected by optical fiber or free space links. The secret keys are negotiated between any pair of QKD nodes, and then they can be delivered to multiple users in various areas for ensuring long-term protection and forward secrecy. We commence by introducing the QKD basics, followed by reviewing the development of QKD networks and their implementation in practice. Subsequently, we describe the general QKD network architecture, its elements, as well as its interfaces and protocols. Next, we provide an in-depth overview of the associated physical layer and network layer solutions, followed by the standardization efforts as well as the application scenarios associated with QKD networks. Finally, we discuss the potential future research directions and provide design guidelines for QKD 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.
Information security faces unprecedented challenges in the digital age, particularly in the face of cyber threats and the emergence of quantum computing. This research examines QKD as a solution for secure communications in urban fiber networks. The study analyzes QKD protocols, including BB84 and Twin-Field QKD, implementing a 46-node metropolitan quantum network and key distribution over distances greater than 1002 kilometers. Various transmission media, such as multicore optical fibers and free-space communication, were evaluated, demonstrating high-capacity quantum communication with advanced noise mitigation techniques. The results reveal significant advances in quantum communication security, highlighting the potential of QKD to provide theoretically secure key distribution based on quantum mechanical principles. The research addresses challenges such as transmission loss, environmental disturbances, and network scalability, laying the groundwork for future implementations in metropolitan networks. This work contributes significantly to the standardization of evaluation protocols and metrics, which is crucial for the global adoption of QKD in a world increasingly dependent on cybersecurity, especially in developing smart cities.
Smart grid depends on an advanced communication network to collect information from the power grid, and to disseminate control commands to the control devices. To safeguard the power grid, it is crucial to ensure information confidentiality in the communication networks. Quantum key distribution (QKD) protocols help in generating, and distributing secret keys between communication parties, and such secret keys are required in symmetric cryptography. The combination of QKD protocols, and symmetric cryptography are known to be unconditionally secure, which means information confidentiality can be guaranteed even against an eavesdropper, who has unlimited resources. This article provides a concise review of existing works on QKD protocols, and their applications in smart grid communications. Deploying QKD protocols in smart grid is challenging because distance between the control center, and control devices can be larger than the limits of existing protocols. Also, QKD protocols require an expensive quantum channel between each pair of sender, and receiver nodes, and there is large number of control devices with diverse capabilities in smart grid. We have classified existing works based on the challenges they have dealt with. Compared to the rich literature on QKD protocols in general, there are significantly fewer works in the specific context of smart grid. This can be an indication for opportunity to make a significant contribution. We have also identified a few research challenges that can be potential future works.
Quantum key distribution is a revolutionary way of quantum cryptography which guarantees absolute security by using the fundamental principle of quantum mechanics. Quantum network consist of two or more nodes of QKD connected via optical fiber or free space. Free space channel can connect two nodes at distances more than 1000Km s apart, whereas fiber links will be used to connect the end users in nearby vicinity. Here we present a study on potential quantum key distribution protocol which can be used in the future quantum network, leading to quantum internet on large scale.