Recent advances on quantum key distribution overcoming the linear secret key capacity bound

Abstract

A crucial goal for quantum key distribution (QKD) is to transmit unconditionally secure keys over long distances. Previous studies show that the key rate of point-to-point QKD is limited by a secret key rate capacity bound, and higher key rates would require quantum repeaters. In 2018, the seminal twin-field (TF) QKD protocol was proposed to provide a remarkable solution to overcoming the linear secret key capacity bound. This article presents an up-to-date survey on recent developments in this area, including the security proofs of phase-matching QKD and other TF-QKD type protocols, the theoretical examinations of these protocols under realistic conditions, and the recent experimental demonstrations.

10 figures, 1 table, 24 pages

References in corpus (11)

• Satellite-to-ground quantum key distribution
• Secure Quantum Key Distribution
• Hacking commercial quantum cryptography systems by tailored bright illumination
• Distillation of secret key and entanglement from quantum states
• 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
• Experimental quantum key distribution beyond the repeaterless secret key capacity
• Direct and Reverse Secret-Key Capacities of a Quantum Channel
• Ultra-high bandwidth quantum secured data transmission
• Asymmetric sending or not-sending twin-field quantum key distribution in practice
• Phase-Matching Quantum Cryptographic Conferencing