Overcoming the rate-distance limit of device-independent quantum key distribution

Abstract

Device-independent quantum key distribution (DIQKD) exploits the violation of a Bell inequality to extract secure key even if the users' devices are untrusted. Currently, all DIQKD protocols suffer from the secret key capacity bound, i.e., the secret key rate scales linearly with the transmittance of two users. Here we propose a heralded DIQKD scheme based on entangled coherent states to improve entangling rates whereby long-distance entanglement is created by single-photon-type interference. The secret key rate of our scheme can significantly outperform the traditional two-photon-type Bell-state measurement scheme and, importantly, surpass the above capacity bound. Our protocol therefore is an important step towards a realization of DIQKD and can be a promising candidate scheme for entanglement swapping in future quantum internet.

5 pages, 3 figures

References in corpus (7)

• Device-independent security of quantum cryptography against collective attacks
• Hacking commercial quantum cryptography systems by tailored bright illumination
• Measurement device independent quantum key distribution over 404 km optical fibre
• Sending-or-Not-Sending with Independent Lasers: Secure Twin-Field Quantum Key Distribution Over 509 km
• Secure device-independent quantum key distribution with causally independent measurement devices
• Proposal for Implementing Device-Independent Quantum Key Distribution based on a Heralded Qubit Amplification
• Beating the fundamental rate-distance limit in a proof-of-principle quantum key distribution system

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• Advances in quantum entanglement purification
• Long-distance twin-field quantum key distribution with entangled sources
• Device-Independent Quantum Key Distribution Using Random Quantum States
• Advantages of Asynchronous Measurement-Device-Independent Quantum Key Distribution in Intercity Networks
• Scalable High-Rate Twin-Field Quantum Key Distribution Networks without Constraint of Probability and Intensity
• Quantum key distribution based on orthogonal state encoding
• Phase-Matching Quantum Key Distribution without Intensity Modulation
• Experimentally Certified Transmission of a Quantum Message through an Untrusted and Lossy Quantum Channel via Bell's Theorem