Network emulators are essential in testing network systems, applications, and protocols. Emulators bridge the gap between simulation setups that lack realism in results and real-world trials that are accurate but often expensive, non-reproducible, and uncontrollable. This paper describes the simulations and emulations of the national Czech QKD network. Using emulation techniques, a unique ecosystem is formed that includes the processes of generating, processing, storing, and consuming cryptographic keys. The presented tool will undoubtedly spur future development, understanding, and teaching, and it is critical for testing novel applications and protocols applied to QKD networks.

Quantum Key Distribution (QKD), a secret key agreement primitive, makes possible long-awaited real-world Information-Theoretical Security (ITS). In the last twenty years, the development of QKD-based networks that deliver ITS keys to distant parties has been a focus of the academic and industry sectors. Several key-delivery specifications have been developed for the practical delivery of keys to end applications. In this paper, we discuss key-delivery specifications with a focus on security and authentication.

The development of telecommunications networks sets greater appetites to ensure secure communication flows. One of the approaches to providing information-theoretical levels of security is the application of quantum cryptography based on the quantum laws of nature. However, quantum networks differ significantly from existing networks in terms of their organization and availability of resources. This technology’s convergence largely depends on how it is integrated into existing networks and on the economic return of investment. Towards analyzing the latter, we consider the business model for accessing QKD network resources through a mechanism of pricing a QKD link upon a user’s request, with continuous fairness monitoring of the network utilization.

Network emulators play an important role in testing network systems, applications, and protocols. Emulators bridge the gap between simulation setups that lack realism in results and real-world trials that are accurate but often expensive, non-reproducible, and uncontrollable. This article presents an extended model of the Quantum Key Distribution Network Simulation Module (QKDNetSim) with a model catalog of QKD components and functionalities. We explore emulations of point-to-point connections in QKD networks and the interaction of essential components within QKD nodes. The presented tool will undoubtedly spur future development and teaching, and it is critical for testing novel applications and protocols applied to QKD networks.

Software-Defined Networking (SDN) is the actual approach in the network design, based on separating the control and data plane. Such architectural model has brought improvements in terms of network monitoring, management and troubleshooting, but has also increased risks related to network security. Security attacks can occur at all SDN layers and disrupt part or the entire network. Existing research is mostly focused on the security of the control plane, since it contains all control logic of SDN networks and thus represents their main part. Although the data plane has many vulnerabilities and can also be a significant source of security threats towards the control plane, it is only partially covered in existing research, without enough details related to differences between methods and implementation techniques which provide security enhancement. In this paper, we present a comprehensive survey on security of the data plane, focusing on the latest advanced solutions. The survey starts with an overview of attacks, threats and affected security attributes in the data plane, classified using common security models: STRIDE, CIA and AAA. After that, we present a detailed analysis of solutions explored in the literature, including the methods used for security enhancement, implementation techniques, experimental environments, their contributions in terms of vulnerabilities that they address, performance analysis and limitations. Through this analysis, we introduce the concept of adaptive security and select several mechanisms which can be used to achieve it. Additionally, we propose possible combinations of presented mechanisms to provide strong, comprehensive solution which should adapt to dynamics of network, attackers and users, and in that way protect the network from different threats and also satisfy the requirements of services which need different levels of security.

Secure communication makes the widespread use of telecommunication networks and services possible. With the constant progress of computing and mathematics, new cryptographic methods are being diligently developed. Quantum Key Distribution (QKD) is a promising technology that provides an Information-Theoretically Secure (ITS) solution to the secret-key agreement problem between two remote parties. QKD networks based on trusted relay nodes are built to provide service to a larger number of parties at arbitrary distances. They function as an add-on technology to traditional networks, generating, managing, distributing, and supplying ITS cryptographic keys. Since key resources are limited, integrating QKD network services into critical infrastructures necessitates effective key management. As a result, this article provides a comprehensive review of key management approaches for trusted-relay QKD networks. They are analyzed to facilitate the identification of potential strategies and accelerate the future development of QKD networks.

In the ongoing discourse surrounding integrating QKD networks as a service for critical infrastructures, key storage design often receives insufficient attention. Nonetheless, it bears crucial significance as it profoundly impacts the efficiency of QKD network services, thereby shaping its suitability for diverse applications. In this article, we analyze the effectiveness of key storage designs developed through practical testbeds and propose a novel key storage design to increase the effectiveness of key creation and supply. All key storage designs underwent analysis using network simulation tools, and the findings demonstrate that the novel key storage design surpasses existing approaches in terms of performance.

Quantum Key Distribution (QKD), a novel secret key agreement primitive, enables long-awaited practical Information-Theoretical Security (ITS). Over the last two decades, academic and industrial communities have devoted their time and resources to developing QKD- based networks that distribute ITS keys to remote parties. However, because of the limited availability of QKD network testbeds to the larger research community and the difficulty and cost of their deployment, progress in this area has been noticeably slow. To that end, we provide an analysis of selected simulated use-cases from the EU H2020 OPENQKD project using the QKDNetSim network simulator. The tool has been extensively upgraded to test novel network management methodologies applied to large-scale QKD networks.

IP devices are ubiquitously spread, for both residential and industrial purposes, thanks to the low integration costs and rapid development cycle of all-IP-based 5G+ technologies. As a consequence, the engineering community now considers their automatization and energy scheduling/management as relevant research fields. These topics have a striking relevance also for the development of smart city networks. As a drawback, most ID-device applications produce a large amount of data (high-frequency complexity), requiring supervised machine learning algorithms to be properly analyzed. In this research, we focus on the performance of vehicular mobility and imaging systems, recognizing scenarios (with powered-on devices) in real-time, with the help of a simple convolutional neural network, proving the effectiveness of such an innovative low-cost approach.