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.
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.
Quantum key distribution (QKD) has potential to provide long-term security for communications across the Internet. As security-hungry applications dramatically rise nowadays, a growing number of QKD networks are promising to be deployed in the immediate future. Nevertheless, a high-security-demand institution (e.g., a bank) needs to pay a high price to deploy its dedicated QKD network, while a cost-effective way of overcoming this challenge is to make multiple tenants share a QKD network. Each tenant represents a high-security-demand institution and can obtain secret keys on demand from the QKD network infrastructure for security purposes. Hence, how to achieve efficient and flexible multi-tenant provisioning over a QKD network becomes a crucial problem. This work introduces software defined networking (SDN) to address this problem. We experimentally demonstrate multi-tenant provisioning (including tenant establishment, adjustment, and deletion) over SDN-enabled metropolitan area QKD networks. A SDN-enabled metropolitan area QKD network architecture is introduced. We present a workflow, protocol extensions, and an on-demand secret-key resource allocation strategy for multi-tenant provisioning, which are all demonstrated by establishing an experimental testbed in the lab. Experimental results verify the effectiveness and flexibility of our SDN-based approaches for multi-tenant provisioning over metropolitan area QKD networks. Moreover, we conduct the simulation and discover the ways of improving the success probability of multi-tenant provisioning over metropolitan area QKD networks.
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.
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.
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) networks can theoretically generate quantum secret keys that are completely secure for an entire communication system. The rate of key distribution is low and decreases exponentially with increasing distance. A classic trusted relay (CTR) uses additional keys to enhance security distance in QKD networks. In practice, the assurance of security for certain relay nodes is still lacking, despite the fact that CTR requires that all nodes be trusted. Owing to channel unreliability, system faults accumulate during the key relay, thereby increasing the probability of CTR failing to distribute the secret key. The failure of a successful key relay would then result in the subsequent destruction of all the keys involved in the process, which leads to the wasting of the quantum secret key and reduction system encryption. Accordingly, reducing the impact of CTR failures and realising the key security distribution of remote quantum networks have become new challenges that require the development of a new survivability scheme. In this study, a software-defined networking (SDN) technique is introduced to circumvent this drawback by utilising the flexibility provided by the SDN paradigm for better QKD network management efficiency. In particular, a novel survivability model called software-defined quantum key relay failure (SDQKRF) is proposed in this paper in which a new function is developed and added to the SDN controller. According to the simulation results, SDN over a QKD network using the SDQKRF model is more reliable and performs better in terms of the key generation ratio, key utilisation rate, recovery after failure, avalanche effect, and service blocking rate than a regular QKD network without the SDQTRF model.