International Conference on Quantum Communications, Networking, and Computing (QCNC)
Quantum Key Distribution Network Architectures
Momtchil Peev, Vicente Martín, Juan P. Brito, Laura Ortíz, Chi‐Hang Fred Fung, Rubén B. Méndez, Jaime S. Buruaga, Rafael J. Vicente, Alberto Sebastián-Lombraña, Julio Setien, Carmen Escribano, Pedro J. Salas, Javier Faba, Rafael Cantó, Antonio Pastor‐Perales, Juan Morales, Jesús Folgueira, Diego R. Lopez
Up to now, Quantum Key Distribution (QKD) Network architectures were confined to relatively small networks. Some theoretical and standardization work was carried out at the framework level but its real-world application is still to be proven. Here, we present a novel architecture for QKD Networks, which is based on the SDN approach, and the components needed to scale to large networks. A well-defined functionality of a minimal set of universal modules allows to define the flow of information among them, and this specifies their interfaces and the architecture. We show that this scheme allows to reuse many already proposed interface definitions requiring just minor adaptation and facilitating the real-world deployment. A QKD Network testbed demonstration following these principles is mentioned. We further elaborate on interfaces needed to scale to very large networks, enabling orchestrations of different types or network monitoring tools. The latter have not been considered in depth up to now, but are needed to support automation and advanced capabilities, multidomain networks, slicing, heterogeneity, resource discovery, etc., which will be necessary to scale to large networks. The dynamicity of the quantum level in this scheme allows a significant reduction of the need of QKD devices on the metropolitan scale, an increased robustness of the service, improving its quality and overall network management, showing that the presented architecture is highly appropriate for telecom operators.
Up to now, Quantum Key Distribution (QKD) Network architectures were confined to relatively small networks. Some theoretical and standardization work was carried out at the framework level but its real-world application is still to be proven. Here, we present a novel architecture for QKD Networks, which is based on the SDN approach, and the components needed to scale to large networks. A well-defined functionality of a minimal set of universal modules allows to define the flow of information among them, and this specifies their interfaces and the architecture. We show that this scheme allows to reuse many already proposed interface definitions requiring just minor adaptation and facilitating the real-world deployment. A QKD Network testbed demonstration following these principles is mentioned. We further elaborate on interfaces needed to scale to very large networks, enabling orchestrations of different types or network monitoring tools. The latter have not been considered in depth up to now, but are needed to support automation and advanced capabilities, multidomain networks, slicing, heterogeneity, resource discovery, etc., which will be necessary to scale to large networks. The dynamicity of the quantum level in this scheme allows a significant reduction of the need of QKD devices on the metropolitan scale, an increased robustness of the service, improving its quality and overall network management, showing that the presented architecture is highly appropriate for telecom operators.
The difficulties related to operating basic quantum communication technologies and the inherent limitations of their direct transmission distances, be these be a consequence of absorption or optical aperture, leads to the fact that current generations of Quantum Key Distribution (QKD) systems are essentially designed to work in a stand-alone mode on a single link. This limits their utility and the potential impact on the market. To avoid these barriers, it is necessary to advance towards systems built for a network. QKD systems have to perform as network devices, and ideally on an equal footing with other telecom devices, without requiring any specialized or ad hoc tuning. To achieve this “zero-touch” integration, it is necessary to build a software ecosystem. This software should take a bare QKD system and provide all the information, so that the network can manage and the applications use the system. Here we present a SW architecture, based on components with a well-defined functionality, to build the SW ecosystem needed to deploy QKD systems in networks. The components support traditional and Software Defined Networks (SDN), as well as separated or integrated (sharing infrastructure) networks to improve their industrialization.
The advent of cryptographically relevant quantum computers poses an existential threat to classical public-key infrastructure. Quantum Key Distribution (QKD) addresses this challenge by providing information-theoretic security for key establishment, independently of any computational hardness assumption. In this work, the deployment and experimental validation of a metropolitan-scale quantum-secure network between data centers in Milan is reported. The network operates over installed fiber infrastructure and implements a layered architecture integrating QKD hardware, standards-compliant Key Management (KM), and centralized Software-Defined Networking (SDN) orchestration. Dynamic path reconfiguration via active optical switching and trusted-node routing allow automated fail-over solutions. Application-layer validation across diverse protocols and workloads confirms the seamless interoperability of all system components. These results establish the technical and operational readiness of metropolitan QKD networks for production deployment, and offer a replicable blueprint for building quantum-secure communication infrastructure at metropolitan scale.
As an important support for quantum communication, quantum key distribution (QKD) networks have achieved a relatively mature level of development, and they face higher requirements for multi-user end-to-end networking capabilities. Thus, QKD networks need an effective management plane to control and coordinate with the QKD resources. As a promising technology, software defined networking (SDN) can separate the control and management of QKD networks from the actual forwarding of the quantum keys. This paper systematically introduces QKD networks enabled by SDN, by elaborating on its overall architecture, related interfaces, and protocols. Then, three-use cases are provided as important paradigms with their corresponding schemes and simulation performances.
Quantum Key Distribution (QKD) is one of the major cryptographic solutions to tackle the security threats associated to future computational advances, in particular those coming from quantum computing. At the most simple level, QKD can be seen as a highly secure source of symmetric secret keys in two separated places. Nonetheless, the lack of standardization and the strong requirements from the physical layer makes this technology very difficult to integrate in existing infrastructure.However, the success of QKD networks radically depends on the degree in which they can be adopted in the existing infrastructure, and it is a must that it happens via standard protocols and interfaces. The flexibility of novel network paradigms, like Software-Defined Networking (SDN), allows for a faster adoption of new concepts, hardware and services in telecommunications networks. This paradigm can be used for quantum communications, allowing for a fast and scalable deployment of quantum technologies and services in the telecommunications network to a degree that was simply impossible in previous schemes, where the different network devices and their connections should be modified, one by one, to create a quantum communications channel.This tutorial provides an introduction to existing QKD technologies and networks, followed by a descriptive explanation on how SDN principles can be utilized to abstract and integrate QKD systems as part of the network management. This will help to reduce the time-to-market for quantum technologies, and also will make quantum cryptography available as a service to be capitalized by the network operators.
There is a great attention to quantum technologies in the ICT environment. In particular, when dealing with security matters, the most prominent quantum technology is Quantum Key Distribution (QKD). QKD allows the sharing of symmetric keys with information theoretic security (ITS, i.e. independently of the computational power of the attacker) between two remote network nodes. QKD is the only known method to share a key able to reach ITS. During the last two decades, there has been a tremendous technological progress in QKD research, that has led to the availability of QKD network demonstrators.Software Defined Networks (SDN) enables the automation of service provisioning within network operator infrastructures. With the advent of web-scale services and dynamic network requirements, operators can not anymore deploy their services based on manual intervention or using proprietary vendor solutions. Programmability is key in the next-generation network infrastructure and any new technology must be integrated with this paradigm. Let us highlight that this requirement is even more important with virtual environments, where a Virtual Network Function (VNF) can be deployed in any point-of-presence of the operator. The new 5G deployments will enable operators to have edge computing services supporting different capabilities, thus increasing even more the complexity to deliver services without any automation.In spite of the high potential of QKD, this technology has not yet found its path to wide adoption, commercialization and deployment. QKD is a physical technology that requires the existence of a quantum channel, a physical connection able to transmit quantum bits without perturbation, making hard its integration in networks. The aim of this document is to present how QKD can be deployed in next generation infrastructures, based on realistic scenarios. To do so, this paper describes the technological components of the solutions, as well as the use cases that motivate such effort. These use cases are described from a telecommunication provider's point of view, as they are the actors in charge of deploying QKD systems in their networks.
Quantum key distribution networks (QKDNs) enable secure communication even in the age of powerful quantum computers. In the hands of a network operator, which can offer its service to many users, the economic viability of a QKDN increases significantly. The highly challenging operator–user relationship in a large-scale network setting demands additional requirements to ensure carrier-grade operation. Addressing this challenge, this work presents a carrier-grade QKDN architecture, which combines the functional QKDN architecture with the operational perspective of a network operator, ultimately enhancing the economic viability of QKDNs. The focus is on the network and key management aspects of a QKDN while assuming state-of-the-art commercial QKD modules. The presented architecture was rolled out within an in-field demonstrator, connecting the cities of Berlin and Bonn over a link distance of 923 km across Germany. We could show that the proposed network architecture is feasible, integrable, and scalable, making it suitable for deployment in real-world networks. Overall, the presented carrier-grade QKDN architecture promises to serve as a blueprint for network operators providing QKD-based services to their customers.