Fiber-based QKD is a promising solution for enhancing the security of information networks. A secret-key re-allocation strategy is proposed and verified for the failure recovery of key provisioning services in resilient fiber-based QKD networks.
Quantum key distribution (QKD) promises to deliver secure keys, which can be applied for security demands in optical networks by using cost-efficient and scalable lightpaths. To achieve such secure communication, the QKD integrated with optical networks has become a promising scenario to provide key provisioning services in optical networks. As an inevitable problem, the occurrence of failures becomes a challenge for the resiliency of the network. In that context, this paper studies the resilient QKD-integrated optical networks against single link failure. By analyzing and quantifying the key provisioning services, we constructed the secret-key flow model (SKFM) for the failure-affected and failure-unaffected cases. Based on the SKFM, a secret-key recovery strategy (SKRS) including three algorithms (i.e., one-path recovery method (OPRM), multi-path recovery method (MPRM), and time window-based recovery method (TWRM)) is designed to recover failure-affected key provisioning services in the network. The simulation work has been conducted to evaluate the performance of OPRM, MPRM, and TWRM in terms of key-service recovery ratio, secret-key recovery ratio, wavelength consumption ratio, and secret-key consumption ratio. Numerical results show that the three algorithms can recover failure-affected key provisioning services effectively, i.e., the MPRM outperforms the OPRM and the TWRM outperforms the MPRM. Better recovery can be realized by sacrificing more wavelength and secret-key resources, which are also required for the delivery of the QKD in the network. Thus, a trade-off can be achieved between the recovery of key provisioning services and the delivery of the QKD on wavelength resources and secret-key resources.
Secure communication makes the widespread use of telecommunication networks and services possible. With the constant progress of computing and mathematics, new cryptographic methods are being diligently developed. Quantum Key Distribution (QKD) is a promising technology that provides an Information-Theoretically Secure (ITS) solution to the secret-key agreement problem between two remote parties. QKD networks based on trusted relay nodes are built to provide service to a larger number of parties at arbitrary distances. They function as an add-on technology to traditional networks, generating, managing, distributing, and supplying ITS cryptographic keys. Since key resources are limited, integrating QKD network services into critical infrastructures necessitates effective key management. As a result, this article provides a comprehensive review of key management approaches for trusted-relay QKD networks. They are analyzed to facilitate the identification of potential strategies and accelerate the future development of 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.
Quantum key distribution (QKD) is considered a secure solution for key distribution and applied in optical networks to overcome security issues by providing key services in different lightpaths. In optical networks, lightpaths in fibers can be used for the delivery of QKD due to their good transmission performance. Accordingly, optical networks secured by QKD have been regarded as an important paradigm, and survivability in this paradigm is an issue worthy of study. In this paper, we focus on the protection schemes for key services in optical networks secured by QKD. Specifically, in consistency with two characteristics of key services (i.e., the key-updating process and key-volume adaptive routing), two key-volume adaptive protection schemes (i.e., dedicated protection and shared protection) are proposed for the networks against link failures. In such scenarios, the designed key-protection threshold can alleviate the tight network resources caused by the key-updating process. Simulation work has been conducted to evaluate the performance of the proposed schemes in terms of blocking probability, resource utilization, and proportion of secret-key consumption with different key-protection thresholds and update periods. Numerical results show that the two proposed schemes are effective in providing protection. Furthermore, evaluating the impact of protection on network security verifies a trade-off that exists between how much protection can be provided for key services versus the overall security of the network, given a certain resource budget.
Quantum Key Distribution (QKD) networks have emerged the revolutionary technology in ensuring secure communication in the digital age. By utilizing the principles of quantum mechanics, QKD allows two parties to establish a secret key securely, which can subsequently be used for encrypting and decrypting sensitive information. While QKD holds immense promise for enhancing cybersecurity, it also presents several challenges that necessitate further research to achieve its full potential. The research presented here examines the development of QKD networks, their real-world use, as well as the general QKD network architecture and the most recent advancements in QKD network deployments.
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.