Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

International Conference on Transparent Optical Networks

Quantum Aware SDN Nodes in the Madrid Quantum Network

Vicente Martín, Alejandro Aguado, Juan P. Brito, Angel L. Sanz, Pedro J. Salas, Diego R. Lopez, Vı́ctor López, Antonio Pastor‐Perales, Andreas Poppe, Momtchil Peev

Published Jul 1, 2019• 25 citations
Publisher

Abstract

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.

DOI
10.1109/icton.2019.8840338

Related papers

The Madrid Testbed: QKD SDN Control and Key Management in a Production Network

Vicente Martín, Juan P. Brito, Laura Ortíz +13 more

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.

International Conference on Transparent Optical Networks•Jul 2, 2023•7 citations

Enabling Quantum Key Distribution Networks via Software-Defined Networking

Alejandro Aguado, Vı́ctor López, Juan P. Brito +3 more

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.

International Conference on Optical Network Design and Modeling (ONDM)•May 1, 2020•32 citations

The Madrid Quantum Network: A Quantum-Classical Integrated Infrastructure

Vicente Martín, Alejandro Aguado, Pedro J. Salas +13 more

We report on the Madrid Quantum Network, designed to demonstrate that a telecommunications network can also host quantum communications in a unified, logical and physical infrastructure. Using new Quantum Key Distribution systems paired with modern networking paradigms, we demonstrate a high technology readiness level of QKD installing the network in production facilities and running relevant use cases.

OSA Advanced Photonics Congress•Jan 1, 2019•17 citations

Demonstration of Software Defined Network Services Utilizing Quantum Key Distribution Fully Integrated with Standard Telecommunication Network

Diego R. Lopez, Vicente Martín, Vı́ctor López +13 more

We present a demonstration of software defined networking (SDN) services utilizing quantum key distribution (QKD) technology, fully integrated with standard telecommunication network connecting production facilities of Telefonica in Madrid. All communications “co-propagate” over the same fiber infrastructure.

Quantum Reports•Sep 3, 2020•17 citations

SDN-Based Hybrid Quantum-Safe Domain Intercommunication Within MadQCI

Rubén B. Méndez, Jaime S. Buruaga, Rafael J. Vicente +9 more

The importance of quantum-key-distribution (QKD) networks is growing rapidly, not only because the underlying QKD protocol is immune against any (known or unknown) attacks but also as these infrastructures can be operated in a hybrid mode, together with emerging quantum safe, or post quantum cryptography (PQC), public key protocols. Hybrid solutions appear to be the most promising remedy against real-world security risks, posed by prospective quantum computers. Simultaneously, telecommunication operators are embracing novel network paradigms, such as software-defined networking (SDN), due to distinct advantages over traditional approaches. SDN-inspired architectures can also be used for QKD and hybrid QKD-PQC networks. These architectures allow a seamless integration of QKD and hybrid QKD-PQC into production networks, significantly increasing the security of the latter. However, there has only been very limited research on optimal strategies for establishing hybrid connectivity across different organizational domains. The present contribution introduces two methods on interconnecting different technological and administrative domains for such networks. The proposed scheme is QKD-vendor independent and relies heavily on standard and open interfaces. It enables a complete end-to-end communication between applications running on nodes in different domains. It can be used for the secure interconnection of different SDN-based telecommunication domains with additional QKD / hybrid protection and has been tested within the Madrid Quantum-Communication Infrastructure.

International Conference on Quantum Communications, Networking, and Computing (QCNC)•Jul 1, 2024•5 citations

Quantum-Key-Distribution (QKD) Networks Enabled by Software-Defined Networks (SDN)

Hua Wang, Yongli Zhao, Avishek Nag

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.

Applied Sciences•May 21, 2019•32 citations
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.
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.
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.
The importance of quantum-key-distribution (QKD) networks is growing rapidly, not only because the underlying QKD protocol is immune against any (known or unknown) attacks but also as these infrastructures can be operated in a hybrid mode, together with emerging quantum safe, or post quantum cryptography (PQC), public key protocols. Hybrid solutions appear to be the most promising remedy against real-world security risks, posed by prospective quantum computers. Simultaneously, telecommunication operators are embracing novel network paradigms, such as software-defined networking (SDN), due to distinct advantages over traditional approaches. SDN-inspired architectures can also be used for QKD and hybrid QKD-PQC networks. These architectures allow a seamless integration of QKD and hybrid QKD-PQC into production networks, significantly increasing the security of the latter. However, there has only been very limited research on optimal strategies for establishing hybrid connectivity across different organizational domains. The present contribution introduces two methods on interconnecting different technological and administrative domains for such networks. The proposed scheme is QKD-vendor independent and relies heavily on standard and open interfaces. It enables a complete end-to-end communication between applications running on nodes in different domains. It can be used for the secure interconnection of different SDN-based telecommunication domains with additional QKD / hybrid protection and has been tested within the Madrid Quantum-Communication Infrastructure.
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.