Quantum relays for long distance quantum cryptography
- 20 March 2005
- journal article
- research article
- Published by Informa UK Limited in Journal of Modern Optics
- Vol. 52 (5), 735-753
- https://doi.org/10.1080/09500340412331283633
Abstract
Quantum cryptography is on the verge of commercial application. One of its greatest limitations is over long distance—secret key rates are low and the longest fibre over which any key has been exchanged is currently 100km. We investigate the quantum relay, which can increase the maximum distance at which quantum cryptography is possible. The relay splits the channel into sections and sends a different photon across each section, increasing the signal-to-noise ratio. The photons are linked as in teleportation, with entangled photon pairs and Bell measurements. We show that such a scheme could allow cryptography over hundreds of kilometres with today's detectors. It could not, however, improve the rate of key exchange over distances where the standard single section scheme already works. We also show that reverse key reconciliation, previously used in continuous variable quantum cryptography, gives a secure key over longer distances than forward key reconciliation.Keywords
This publication has 17 references indexed in Scilit:
- Long Distance Quantum Teleportation in a Quantum Relay ConfigurationPhysical Review Letters, 2004
- Single-photon interference experiment over 100 km for quantum cryptography system using balanced gated-mode photon detectorElectronics Letters, 2003
- Quantum relays and noise suppression using linear opticsPhysical Review A, 2002
- Quantum key distribution over 67 km with a plug&play systemNew Journal of Physics, 2002
- Security of quantum key distribution with entangled photons against individual attacksPhysical Review A, 2002
- Quantum cryptographyReviews of Modern Physics, 2002
- Quantum Repeaters: The Role of Imperfect Local Operations in Quantum CommunicationPhysical Review Letters, 1998
- Purification of Noisy Entanglement and Faithful Teleportation via Noisy ChannelsPhysical Review Letters, 1996
- Quantum cryptography without Bell’s theoremPhysical Review Letters, 1992
- Quantum cryptography based on Bell’s theoremPhysical Review Letters, 1991