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.
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.
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.
This work addresses the orchestration of large-scale Quantum Key Distribution Networks (QKDNs) using Software Defined Networking (SDN). Building on ETSI and ITU specifications, common best practices and architectures are outlined. The main task of the SDN Controller is to aggregate technical key performance indicators (KPI) from the network and, based on these, select the optimal path. Multiple path selection algorithms, based on Dijkstra or a maximum-minimum capacity algorithm, with built-in load balancing are presented. The algorithms were tested in simulations and their performances, and tradeoffs, are discussed. Additional critical aspects related to SDN controlled QKDNs are discussed, such as query batching, multi-path selection and group key capabilities. An oblivious multi-party protocol is proposed for relay path selection in a multi-domain scenario, so providers don't have to disclose sensitive information about their QKDN. These contributions aim to enhance scalability, resilience and interoperability in quantum-secure network infrastructures.
Quantum key distribution (QKD) holds the potential of providing long-term integrity and confidentiality for data and communications. Currently, many fiber-based QKD systems have been commercialized and several QKD networks have been deployed. Given the high cost and complexity of QKD network deployment, QKD as a service (QaaS) becomes a promising pattern for future QKD networks. The QaaS concept is that multiple users can apply for QKD services to obtain their required secret-key rates (SKRs) from the same QKD network infrastructure instead of deploying their dedicated QKD networks. Accordingly, how to provide efficient and flexible QaaS for fulfilling the SKR requirements of multiple users over a QKD network infrastructure becomes a new challenge. This study introduces the software defined networking (SDN) technique to overcome this challenge, since SDN can add flexibility together with efficient QKD network management. A new framework of SDN for QaaS (SDQaaS) is proposed, where the QaaS functions are developed in the SDN controller. We present the protocol extension, intercommunication workflow, and routing and SKR assignment strategy for QaaS implementation in the SDQaaS framework. We also establish a SDQaaS experimental testbed and perform the numerical simulation to verify our presented approaches. Experimental results demonstrate that our presented approaches can achieve efficient and flexible QaaS over the QKD network. Moreover, simulation results indicate that the success probability of QKD service requests can be increased via lowering the flexibility of SKR requirements for QKD service creation, sacrificing more cost to produce higher SKR over the QKD network, or gradually reducing SKR requirements with the modification of QKD service.
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 cryptography provides an effective approach to address the security challenges in communication network posed by Shor's factorization, Grover's search, and other new algorithms. We propose an architecture of QoS-oriented quantum key distribution network (QKDN) based on network slicing and software-defined network (SDN). The network slices with different QoS levels can be constructed according to users' requirements. The throughput, latency and other QoS metrics requirement can be obtained by allowing for centralized control management and more flexible resource allocation using the scheme of SDN. Simulation results show that slicing scheme in QKDN can flexibly orchestrate resources to meet QoS of the services and can also be easily integrated with existing communication networks.
Software-defined networking (SDN) has emerged as a promising paradigm for managing and controlling network resources efficiently. However, ensuring the security of data packets transmitted within an SDN environment remains a critical challenge. Traditional networking relies on static configurations, while SDN offers dynamic control and programmability, revolutionizing network management. In SDN, the application layer employs tools like OpenDaylight and Mininet for network management and testing. The control layer, managed by controllers such as Floodlight or ONOS, orchestrates traffic flow among switches. In the infrastructure layer, Quantum Key Distribution (QKD) with the BB84 protocol ensures secure communication. Together, these layers enable agile, programmable, and secure networking paradigms. This paper proposes integrating quantum key distribution (QKD) into SDN architectures to bolster packet-level security. By leveraging quantum entanglement and uncertainty, a secure communication channel between SDN controllers and switches is established, resilient to quantum attacks. Evaluation through simulations and real-world experiments demonstrates efficacy in mitigating security threats while minimizing overhead and latency, advancing SDN security IEEE 802.1X capabilities and leveraging quantum technologies for cybersecurity.