International Conference on Transparent Optical Networks
The Madrid Testbed: QKD SDN Control and Key Management in a Production Network
Vicente Martín, Juan P. Brito, Laura Ortíz, Rubén B. Méndez, R. Vicente, Jaime S. Buruaga, A. J. Sebastian, Daniel Gómez Aguado, Marta Irene García Cid, Julio Setien, Pedro J. Salas, Carmen Escribano, E. Dopazo, José Manuel Rivas-Moscoso, Antonio Pastor‐Perales, Diego R. Lopez
Software Defined Networking is increasingly seen as one of the best choices to create a Quantum Key Distribution (QKD) Network, especially if the aim is also its integration into a standard telecommunications network. The degree of flexibility afforded by this paradigm allows the creation of a network whose control mechanisms can be made aware simultaneously of the capabilities installed at the classical optical transport level as well as those at the quantum level. This is interesting not only to manage the coexistence between a classical and a quantum network sharing the same infrastructure, but also for future applications beyond QKD. This flexibility is due to a formal separation between the control and data forwarding planes. The logically centralized SDN controller gathers all relevant information monitoring the behavior of the hole network. It can act on the programmable quantum or classical devices opening many possibilities to share a common infrastructure, that can reach even the level of a single fiber strand to manage the signals that go through it in a compatible way. The same controller can use this information to manage the fundamental task of a QKD network, namely the key transport. Here we briefly report on the implementation of the SDN-QKD controller used in the Madrid testbed and its use to allow multi-vendor end-to-end key transport between any two nodes in the network.
Software Defined Networking is increasingly seen as one of the best choices to create a Quantum Key Distribution (QKD) Network, especially if the aim is also its integration into a standard telecommunications network. The degree of flexibility afforded by this paradigm allows the creation of a network whose control mechanisms can be made aware simultaneously of the capabilities installed at the classical optical transport level as well as those at the quantum level. This is interesting not only to manage the coexistence between a classical and a quantum network sharing the same infrastructure, but also for future applications beyond QKD. This flexibility is due to a formal separation between the control and data forwarding planes. The logically centralized SDN controller gathers all relevant information monitoring the behavior of the hole network. It can act on the programmable quantum or classical devices opening many possibilities to share a common infrastructure, that can reach even the level of a single fiber strand to manage the signals that go through it in a compatible way. The same controller can use this information to manage the fundamental task of a QKD network, namely the key transport. Here we briefly report on the implementation of the SDN-QKD controller used in the Madrid testbed and its use to allow multi-vendor end-to-end key transport between any two nodes in the network.
QKD technology is mature enough to be used beyond the usual single, point to point, link by creating networks. Quantum ad hoc networks, where a separate, quantum-only network, is running in parallel to a classical network have been demonstrated in several occasions. Having to, essentially, duplicate the network to introduce quantum communications is very expensive and, beyond niche use-cases, fully integrated quantum-classical networks is what the industry demands to accept quantum technologies as a serious networking technology, ready for a broad market uptake.Recently we have reported on the successful deployment of the Madrid Quantum Network. This network is novel because it has been the first installed in production sites of a Telecommunications operator and moreover it is managed through a Software Defined Networking (SDN) structure that integrates classical and quantum channels. The network was operating for four months and we could demonstrate several technologies utilizing the integration of quantum and classical networks. Here we report on some implementation aspects and its usage in several use cases, in particular to secure the management of the SDN control plane as a critical infrastructure.
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.
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.
This paper demonstrates the use of software-defined networking (SDN) orchestration to integrate regionally separated networks in which different network parts use incompatible key management systems (KMSs) managed by different SDN controllers to ensure end-to-end QKD service provisioning to deliver the QKD keys between geographically different QKD networks. The study focuses on scenarios in which different parts of the network are managed separately by different SDN controllers, requiring an SDN orchestrator to coordinate and manage these controllers. In practical network deployments, operators often utilize multiple vendors for their network equipment. This practice also enables the expansion of the QKD network's coverage by interconnecting various QKD networks equipped with devices from different vendors. However, as coordinating different parts of the QKD network is a complex task, this paper proposes the implementation of an SDN orchestrator which acts as a central entity to manage multiple SDN controllers, ensuring end-to-end QKD service provisioning to address this challenge. For instance, when there are multiple border nodes to interconnect different networks, the SDN orchestrator calculates the path in advance for the end-to-end delivery of keys between initiating and target applications belonging to different networks. This path selection requires the SDN orchestrator to gather information from each SDN controller managing the respective parts of the QKD network. This work shows the practical implementation of SDN orchestration for interoperable KMS in commercial QKD networks in South Korea. By employing an SDN orchestrator, it becomes possible to coordinate multiple SDN controllers and ensure the efficient and secure delivery of QKD keys between different QKD networks with varying vendor equipment.
Quantum key distribution (QKD) has been identified as a secure method for providing symmetric keys between two parties based on the fundamental laws of quantum physics, making it impossible for a third party to copy the quantum states exchanged without being detected by the sender (Alice) and receiver (Bob) and without altering the original states. However, when QKD is applied in a deployed optical network, physical-layer intrusions may occur in the optical links by injecting harmful signals directly into the optical fiber. This can have a detrimental effect on the key distribution and eventually lead to its disruption. On the other hand, network architectures with software-defined networking (SDN) benefit from a homogeneous and unified control plane that can seamlessly control a QKD-enabled optical network end-to-end. There is no need for a separate QKD control, a separate control for each segment of an optical network, and an orchestrator to coordinate between these parts. Furthermore, SDN allows customized and application-tailored control and algorithm provisioning, such as QKD-aware optical path computation, to be deployed in the network, independent of the underlying infrastructure. Therefore, in this paper, we investigate the integration of the application, SDN, and QKD infrastructure layers and confirm capability for flexible supervision and uninterrupted key service provisioning in the event of link level attacks. An experimental demonstrator is used, for the first time, to verify the architecture proposed, considering real-time monitoring of quantum parameters and fiber-optic link intruders to emulate real-world conditions. Furthermore, attacks on a standard single-mode fiber (via a 3 dB coupler) and a multicore fiber (via an adjacent core) are undertaken to explore different connectivity between QKD units. Results show additional attacker identification and switching time of less than 60 ms for the link cases investigated, being negligible compared to the total (re-)initialization time of 14 min of the QKD units.
Quantum Key Distribution is an emerging technology. On real production networks is starting to be installed due to it can strength robustness in communications and face next threat that Quantum Computing could be in next years if communications are not ready. As a new technology, it is difficult to integrate or interoperate with it without the necessary standards or interfaces, Software Defined Networking is presented as a solution to integrate QKD in real environments thanks to an approach based on standards, models, and interfaces. NETCONF and RESTCONF are protocols well known by the community oriented to manage devices remotely based on models that are integrated on SDN environments, in this sense, a Trusted Node can be configurable and manageable if we consider it as a device instead of a set of elements. In this paper we propose a method for the integration and management of Trusted Nodes on SDN independently of the transport protocol between the SDN logically centralized Controller and each QKD Node to provide end to end symmetric key for final application services