Researchers Model Networks to Secure Telecommunications

The increasing sophistication of quantum computing poses a fundamental threat to current encryption methods, driving the need for fundamentally secure communication systems. Hayato Ishida, Amal Elsokary, and Maria Aslam, from Loughborough University, alongside colleagues at BT Research and Loughborough University, investigate how to build and evolve quantum key distribution networks to meet this challenge. Their work explores existing and proposed network architectures, employing advanced modelling techniques to create flexible and reusable designs. This research demonstrates a systematic approach to developing viable quantum networks, offering a framework for managing rapidly evolving technologies and stakeholder expectations, and providing valuable insights for broader systems engineering integration challenges.

Significant advances in the capabilities of sensors, computing, timing, and communication depend on engineering highly complex systems that integrate quantum devices into existing classical infrastructure. This work explores a range of existing and future quantum communication networks, specifically quantum key distribution network proposals, to model and demonstrate the evolution of quantum key distribution network architectures. Leveraging Orthogonal Variability, the research investigates how these networks can be designed and optimised for practical implementation and scalability.

Adapting Systems Engineering for Quantum Networks

This paper addresses the challenge of applying systems engineering principles to the emerging field of quantum communication networks. The authors recognise that traditional approaches to systems engineering need adaptation to effectively handle the unique characteristics of quantum technologies. Their central contribution is the application of Model-Based Systems Engineering (MBSE), particularly using SysML, to model and analyse quantum network architectures, allowing for a formal, visual, and consistent representation of the system, facilitating communication among stakeholders and enabling early detection of design flaws. The authors emphasise the importance of managing variability in quantum network designs, as these networks can be configured in many ways.

They leverage product line engineering techniques to identify, capture, and manage this variability within the SysML models. By integrating product line engineering principles with MBSE, the paper presents a systematic approach to quantum network design, allowing for the creation of a product family of networks where different configurations can be derived from a common set of core assets. The researchers demonstrate how to model specific quantum key distribution use cases, such as point-to-point communication, networks with trusted nodes, and networks with quantum repeaters, using SysML diagrams. A publicly available GitHub repository accompanies the paper, containing the SysML models, allowing others to reproduce the results and build upon the work.

The authors argue that MBSE provides a valuable framework for managing the complexity of quantum networks, enabling a more systematic and rigorous design process. Integrating product line engineering with MBSE allows for the efficient creation of a family of quantum networks, reducing development costs and time-to-market. SysML is demonstrated to be a capable language for modelling quantum network architectures and capturing the essential characteristics of quantum key distribution protocols and network components. Explicitly managing variability in quantum network designs is crucial to accommodate different requirements and use cases. The MBSE approach allows for early-stage analysis of quantum network designs, identifying potential issues before they become costly to fix.

Quantum Network Design with Adaptable Modelling

Researchers have developed a new framework for designing and implementing quantum communication networks, addressing the complex challenge of integrating cutting-edge quantum technologies with existing classical infrastructure. This work focuses on creating adaptable network architectures capable of evolving alongside rapid advancements in quantum technology and meeting diverse stakeholder requirements. The core of this approach lies in a method for systematically organising knowledge about quantum communication components and translating that knowledge into a visual, easily understandable model. The team’s framework combines Orthogonal Variability Modelling with Systems Modelling Language, creating a structured system for representing the many possible configurations of a quantum network.

Orthogonal Variability Modelling allows for the identification of key variations in network design, such as different types of quantum communication media or satellite arrangements, while Systems Modelling Language provides a standardised visual language for modelling the behaviour of these components. This combination enables engineers to quickly compose initial network architectures tailored to specific needs, rather than starting from scratch each time. The process involves iteratively refining the model based on feedback from both quantum physicists and systems engineers, ensuring both technical accuracy and practical usability. A key innovation is the ability to represent different quantum key distribution protocols, including BB84, MDI-QKD, and Ekert-QKD, within a unified modelling framework.

The researchers demonstrate how complex protocols can be visually represented using standardised diagrams, allowing for easier comparison and integration. They also model the challenges of long-distance quantum communication, illustrating how quantum repeaters could extend the range of these networks, even though this technology is still under development. This framework isn’t limited to purely quantum elements; it also incorporates conventional networking components, allowing for a holistic view of the entire system. This approach offers significant advantages in terms of adaptability and scalability. By separating the core concepts from specific implementations, the framework allows for easy incorporation of new quantum technologies as they emerge. The team successfully demonstrated the framework’s ability to quickly generate initial network designs based on high-level stakeholder requirements.

Key Distribution Networks, A Systems Framework

This work presents a framework for systematically developing key distribution networks, crucial for secure communication in the face of evolving threats to traditional encryption methods. By combining Orthogonal Variability Modelling with the Systems Modelling Language, the researchers demonstrate a method for managing the complexity of these networks and accommodating future changes in stakeholder needs. The resulting traceable artefacts promote modularity and reusability, supporting the investigation of integration challenges beyond key distribution, within the broader field of systems engineering. Future research directions include exploring the application of this framework to other complex systems and refining the modelling techniques to better capture the nuances of quantum technologies. The authors demonstrate a valuable approach to managing complex, evolving systems, offering a pathway towards more robust and adaptable communication networks.