Optimizing the deployment of quantum key distribution switch-based networks.

Area of Science:

• Quantum Information Science
• Network Security
• Applied Physics

Background:

• Quantum Key Distribution (QKD) networks offer information-theoretic security for key exchange.
• Real-world QKD deployment faces challenges including high device costs and limited secret key rates.
• Existing QKD network architectures require numerous expensive single-photon detector devices.

Purpose of the Study:

• To present a novel QKD network architecture that reduces deployment costs.
• To address the economic barriers hindering widespread QKD network adoption.
• To maintain acceptable secret key rates despite cost-saving modifications.

Main Methods:

• Implementation of optical switches within the QKD network infrastructure.
• Reduction in the number of required QKD receiver devices, specifically those with single-photon detectors.
• Modification of the QKD network protocol to accommodate the new architecture.
• Performance estimation for a 670 km, 8-node network link.

Main Results:

• The proposed switch-based QKD architecture achieves significant resource savings, up to 28%.
• The network throughput experiences a minimal reduction of only 8%.
• Demonstrated feasibility and cost-effectiveness for large-scale QKD network deployment.

Conclusions:

• The novel architecture effectively lowers the cost of deploying QKD networks.
• Optical switches and reduced receiver counts are viable strategies for cost optimization.
• This approach balances economic benefits with a negligible impact on network performance.