Next-Generation QKD Systems

Expected Outcome:

This action will strengthen Europe's strategic autonomy in quantum-secure communications by advancing core QKD technologies and integration capabilities. Expected results include:

• Development and demonstration of next-generation QKD systems, with a focus on cost-effectiveness and integration, with specific measurable improvements in one of the following parameters or features: (i) key rate (>1 Mbps over metropolitan distances), (ii) operational coverage of a network at the regional scale, >300 km for fibre-based QKD, including e.g. twin field and free-space links also for non-wired segments and for redundancy, (iii) development and demonstration of advanced quantum cryptographic protocols beyond QKD with provable security advantage over classical cryptographic systems. Implementation of hybrid quantum-classical cryptographic frameworks combining QKD and post-quantum cryptography (PQC), tested on clearly defined real-world applications.

• Integration of quantum communication components with network equipment and orchestration systems (e.g., software-defined networking).

• Validation of QKD-based security in high-priority use cases beyond EuroQCI infrastructure, including: • Critical infrastructure monitoring (e.g., energy grid telemetry),

• Long-term secure cloud storage,

• Industrial control systems (e.g., transport, manufacturing),

• Secure multi-site enterprise communications.

• Strengthened European supply chain through the development of certifiable, standardised, and scalable QKD components.

• This action must address at least two core technical roadblocks defined in the SRIA 2030 for quantum-secure communication. These include scalability challenges in next-generation QKD protocols (e.g. MDI-QKD, DI-QKD) and the integration of QKD with PQC. Proposals are also encouraged to target at least one functionality beyond QKD in prepare-and-measure and one in entanglement-based scenarios, as identified for future quantum networks in the SRIA 2030.

Scope:

The action should support applied R&D in advanced QKD systems and their integration into future secure communication networks, avoiding overlap with EuroQCI deployment efforts. Proposals must include:

• Development and experimental validation of advanced QKD protocols and systems such as: • Continuons-variable QKD (CV-QKD),

• Measurement-device-independent or device-independent QKD,

• Twin-field QKD (TF-QKD),

• Design and implementation of QKD integration into classical and optical networking infrastructure: • Compatibility with existing network equipment (e.g., routers, switches),

• Interface development for SDN/NFV orchestration platforms,

• Secure key management compatible with enterprise-grade services.

• Demonstration of hybrid QKD-PQC frameworks in at least two realistic and demanding use cases, with demonstrable benefits over classical-only solutions.

• In addition to the QKD-focused activities, the action may also address research and first-demonstration efforts on novel quantum communication protocols beyond QKD. This includes the design, feasibility analysis, and early experimental validation of quantum primitives for security and trust in distributed and decentralized settings. These efforts should explore the implications of such protocols on future hardware and architectural choices and contribute to the long-term vision of quantum networks, as defined in the SRIA 2030.

• Validation of security performance through well-defined benchmarks and verification methods supporting the outcomes from EU quantum certification projects.

• Development of interoperable, scalable, and certifiable QKD hardware and software components (e.g., quantum random number generators, integrated photonic QKD components, single photon detectors, network controllers) supporting certification, in coordination with other specific EU programs, such as Euro-QCI..

• Provision of cloud-accessible interfaces to QKD resources to facilitate remote experimentation and integration testing.

• Establishment of at least one demonstrator involving end-users in a live operational setting, with KPIs for availability, key rate, and resilience under different network conditions.

• Contribution to standards and certification activities to support widespread adoption and regulatory compliance.

• Engagement with industry and national network operators to ensure compatibility with telecom-grade requirements and avoid duplication with EuroQCI infrastructures, focusing instead on advancing the technology readiness of next-generation systems.

This action should build on the results of the QSNP Framework Partnership Agreement and align with the SRIA 2030, the Quantum Europe Strategy and EuroQCI, targeting technology readiness and practical deployment pathways for quantum-secure communications.