Protocol choice and parameter optimization in decoy-state measurement-device-independent quantum key distribution

Abstract

Measurement-device-independent quantum key distribution (MDI-QKD) has been demonstrated in both laboratories and field-tests using attenuated lasers combined with the decoy-state technique. Although researchers have studied various decoy-state MDI-QKD protocols with two or three decoy states, a clear comparison between these protocols is still missing. This invokes the question of how many types of decoy states are needed for practical MDI-QKD. Moreover, the system parameters to implement decoy-state MDI-QKD are only partially optimized in all previous works, which casts doubt on the actual performance of former demonstrations. Here, we present analytical and numerical decoy-state methods with one, two and three decoy states. We provide a clear comparison among these methods and find that two decoy states already enable a near optimal estimation and more decoy states cannot improve the key rate much in either asymptotic or finite-data settings. Furthermore, we perform a full optimization of system parameters and show that full optimization can significantly improve the key rate in the finite-data setting. By simulating a real experiment, we find that full optimization can increase the key rate by more than one order of magnitude compared to non-optimization. A local search method to optimize efficiently the system parameters is proposed. This method can be four orders of magnitude faster than a trivial exhaustive search to achieve a similar optimal key rate. We expect that this local search method could be valuable for general fields in physics.

11 pages

References in corpus (9)

• Device-independent security of quantum cryptography against collective attacks
• Free-Space distribution of entanglement and single photons over 144 km
• Hacking commercial quantum cryptography systems by tailored bright illumination
• Experimental Long-Distance Decoy-State Quantum Key Distribution Based On Polarization Encoding
• Long distance decoy state quantum key distribution in optical fiber
• Gigahertz decoy quantum key distribution with 1 Mbit/s secure key rate
• Quantum Eavesdropping without Interception: An Attack Exploiting the Dead Time of Single Photon Detectors
• Statistical fluctuation analysis for measurement-device-independent quantum key distribution
• Resilience of gated avalanche photodiodes against bright illumination attacks in quantum cryptography

Cited by in corpus (10)

• Measurement device independent quantum key distribution over 404 km optical fibre
• Improved statistical fluctuation analysis for measurement-device-independent quantum key distribution with three-intensity decoy-state method
• Measurement-device-independent quantum cryptography
• Measurement-device-independent quantum key distribution with source state errors and statistical fluctuation
• Measurement-device-independent quantum key distribution with source state errors in photon number space
• Experimental asymmetric Plug-and-Play Measurement-device-independent quantum key distribution
• Detector-Device-Independent Quantum Key Distribution
• Simulating single photons with realistic photon sources
• Loss-tolerant quantum secure positioning with weak laser sources
• A cost-effective measurement-device-independent quantum key distribution system for quantum networks