Quantum key distribution (QKD) is a novel technology that can be seen as a synchronized source of symmetric keys in two separated domains that is immune to any algorithmic cryptanalysis. This technology makes impossible to copy the quantum states exchanged between two endpoints. Therefore, if implemented properly, QKD generates keys of the highest security based on the fundamental laws of quantum physics. No algorithmic advance would force a change of technology, as opposed to current public key cryptographic protocols, that rely on the complexity of certain mathematical problems. These protocols are at risk due to the advances in quantum computing and should be changed. On the other hand, network services are increasingly requesting more flexibility and network resources. One of the most desired capabilities is having higher level of security for the transmission between remote premises. In this work, we propose a node architecture to provide QKD-enhanced security in end-to-end (E2E) services and analyze the control plane requirements in order to provide such services in transport networks. This work defines and demonstrates for the first time extensions for generalized multi-protocol label switching (GMPLS) networks. Results show how these new services could be integrated in existing operators' control plane architectures.
Quantum key distribution (QKD) is a novel technology that can be seen as a synchronized source of symmetric keys in two separated domains that is immune to any algorithmic cryptanalysis. This technology makes impossible to copy the quantum states exchanged between two endpoints. Therefore, if implemented properly, QKD generates keys of the highest security based on the fundamental laws of quantum physics. No algorithmic advance would force a change of technology, as opposed to current public key cryptographic protocols, that rely on the complexity of certain mathematical problems. These protocols are at risk due to the advances in quantum computing and should be changed. On the other hand, network services are increasingly requesting more flexibility and network resources. One of the most desired capabilities is having higher level of security for the transmission between remote premises. In this work, we propose a node architecture to provide QKD-enhanced security in end-to-end (E2E) services and analyze the control plane requirements in order to provide such services in transport networks. This work defines and demonstrates for the first time extensions for generalized multi-protocol label switching (GMPLS) networks. Results show how these new services could be integrated in existing operators' control plane architectures.
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) 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.
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.
Quantum Key Distribution (QKD) has progressed from a theoretical cryptographic concept to an emerging secure communication infrastructure technology. While early work focused on protocol security and physical-layer feasibility, current research increasingly addresses scalable network deployment, hardware acceleration, and integration with classical communication systems. As QKD expands from point-to-point links to metropolitan, backbone, and hybrid satellite–terrestrial networks, new engineering challenges arise in topology design, entropy generation, real-time key distillation, and multi-vendor interoperability. This survey provides an infrastructure-oriented review of QKD networks, examining architectural models, quantum randomness as a root of trust, FPGA and system-on-chip (SoC) based acceleration techniques, and programmable control-plane integration. Key management system architectures and standardized interfaces are analyzed to highlight their roles in enabling scalable, interoperable deployments. The paper also synthesizes major standardization efforts and deployment initiatives shaping carrier-grade QKD infrastructures. Finally, open engineering challenges, including scalability, control-plane integration, certification harmonization, and hybridization with post-quantum cryptography, are identified, positioning QKD as a foundational component of next-generation secure communication systems.
Dynamic and flexible optical networking combined with virtualization and softwarisation enabled by network function virtualization (NFV) and software defined networking (SDN) are the key technology enablers for supporting the dynamicity, bandwidth, and latency requirements of emerging 5G network services. To achieve the end-to-end connectivity objective of 5G, network services (NSes) must be often deployed transparently over multiple administrative and technological domains. Such scenario often presents security risks since a typical NS11Network service is a combination of multiple virtual and physical network functions created to realise a desired network functionality. may comprise a chain of network functions, each executed in different remote locations, and tampering within the network infrastructure may compromise their communication. To avoid such threats, quantum key distribution (QKD) has been identified and proposed as a future-proof method immune to any algorithmic cryptanalysis based on fundamental quantum-physics mechanisms to distribute symmetric keys. The maturity of QKD has enabled the research and development of quantum networks with gradual coexistence with classical optical networks using carrier-grade telecom equipment. This makes the QKD technology a suitable candidate for security of distributed and virtualised network services. In this article, for the first time, we propose a dynamic quantum-secured optical network for supporting network services that are dynamically created by chaining virtual network functions (VNFs)22Hardware network functions when implemented in software and deployed as VMs or containers are called VNFs. over multiple network domains. This work includes a new flex-grid quantum-switched reconfigurable optical add drop multiplexer (q-ROADM), extensions to SDN-enabled optical control plane, and extensions to NFV orchestration to achieve quantum-aware, on-demand chaining of VNFs. The experimental results verify the capability of routing quantum and classical data channels both individually and dynamically over shared fibre links. Moreover, quantum secured chaining of VNFs in 5G networks is experimentally demonstrated via interconnecting four autonomous 5G islands simultaneously through the q-ROADM with eight optical channels using the 5GUK Exchange orchestration platform. The experimental scenarios and results confirm the benefit of the proposed data plane architecture and control/management plane framework.
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.