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.
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.
Software-Defined Networking (SDN) is an emerging networking paradigm that decouples the control and data plane in order to enable programmable and flexible networks, optimizing its applications and advancing computer systems. It does so through its architecture, a key part of which is a centralized network management through open interfaces that revolutionizes the way in which networks are designed and makes them more agile and versatile to the evolving needs of modern and future applications services. This also means, however, that there is now a centralized point of attack that is a major vulnerability, threatening the security of the entire network. With such an advanced network paradigm, it requires a security system that will mitigate these risks and warrant long-term security. In attempts to allow secure communications within the network, this research proposes the implementation of Quantum Key Distribution (QKD), leveraging quantum mechanics to secure the network against any computational advancements in the future. QKD is a recent cryptographic system that includes a traditional-computational channel and a physical-quantum channel to generate and distribute keys between parties. It uses the principles of quantum mechanics including entanglement and superposition to ensure that the physical layer cannot be compromised computationally. QKD provides confidentiality and privacy of information and communication. Moreover, it is resistant to technological advancements. The implications of QKD significantly enhance SDN security through its protection against attacks, efficient key distribution, reliable network orchestration, and data integrity, creating an architecture that establishes stable communication channels that are resistant to cyber threats.
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.
Today’s networks are quickly evolving toward more dynamic and flexible infrastructures and architectures. This software-based evolution has seen its peak with the development of the software-defined networking (SDN) and network functions virtualization (NFV) paradigms. These new concepts allow operators to automate the setup of services, thus reducing costs in deploying and operating the required infrastructure. On the other hand, these novel paradigms expose new vulnerabilities, as critical information travels through the infrastructure from central offices, down to remote data centers and network devices. Quantum key distribution (QKD) is a state-of-the-art technology that can be seen as a source of symmetric keys in two separated domains. It is immune to any algorithmic cryptanalysis and is thus suitable for long-term security. This technology is based on the laws of physics, which forbids us from copying the quantum states exchanged between two endpoints from which a secret key can be extracted. Thus, even though it has some limitations, a correct implementation can deliver keys of the highest security. In this paper, we propose the integration of QKD systems with well-known protocols and methodologies to secure the network’s control plane in an SDN and NFV environment. Furthermore, we experimentally demonstrate a workflow where QKD keys are used together with classically generated keys to encrypt communications between cloud and SDN platforms for setting up a service via secure shell, while showcasing the applicability to other cryptographic protocols.
As quantum computers advance, they pose a growing threat to traditional encryption methods that protect sensitive information. Quantum Key Distribution (QKD) offers a secure alternative by using quantum mechanics to create shared secret keys whose interception can be detected. Integrating this technology into existing networks is essential to enable quantum-safe communications without requiring new infrastructure. This dissertation explores how Continuous-Variable Quantum Key Distribution (CV-QKD) systems can be integrated into current network infrastructures. It discusses relevant models, architectures, and standards that support this integration, focusing on how the SoftwareDefined Networking (SDN) model can standardize and simplify communication between QKD systems and traditional networks.
The nature of network services has drastically changed in recent years. New demands require new capabilities, forcing the infrastructure to dynamically adapt to new scenarios. Novel network paradigms, such as software-defined networking (SDN) and network functions virtualization, have appeared to provide flexibility for network management and services. The reliance on software and commoditized hardware of these new paradigms introduces new security threats and, consequently, one of the most desired capabilities is a strengthened security layer when connecting remote premises. On the other hand, traditional cryptographic protocols are based on computational complexity assumptions. They rely on certain mathematical problems (e.g., integer factorization, discrete logarithms, or elliptic curves) that cannot be efficiently solved using conventional computing. This general assumption is being revisited because of quantum computing. The creation of a quantum computer would put these protocols at risk and force a general overhaul of network security. Quantum key distribution (QKD) is a novel technique for providing synchronized sources of symmetric keys between two separated domains. Its security is based on the fundamental laws of quantum physics, which makes it impossible to copy the quantum states exchanged between both endpoints. Therefore, if implemented properly, QKD generates highly secure keys, immune to any algorithmic cryptanalysis. This work proposes a node design to provide QKD-enhanced security in end-to-end services and analyze the control plane requirements for service provisioning in transport networks. We define and demonstrate the necessary workflows and protocol extensions in different SDN scenarios, integrating the proposed solution into a virtual router providing QKD-enhanced IPsec sessions.
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.