Secure coherent-state quantum key distribution protocols with efficient reconciliation

Journal Article · Sun May 15 04:00:00 EDT 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.71.052304· OSTI ID:20717715

Assche, G van; Cerf, N J ^[1]; Iblisdir, S ^[1]

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1. QuIC, Ecole Polytechnique, Universite Libre de Bruxelles, CP 165/59, 1050 Brussels (Belgium)

We study the equivalence of a realistic quantum key distribution protocol using coherent states and homodyne detection with a formal entanglement purification protocol. Maximally entangled qubit pairs that one can extract in the formal protocol correspond to secret key bits in the realistic protocol. More specifically, we define a qubit encoding scheme that allows the formal protocol to produce more than one entangled qubit pair per entangled oscillator pair or, equivalently for the realistic protocol, more than one secret key bit per coherent state. The entanglement parameters are estimated using quantum tomography. We analyze the properties of the encoding scheme and investigate the resulting secret key rate in the important case of the attenuation channel.

• OSTI ID: 20717715
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 5 Vol. 71; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ANNIHILATION OPERATORS
ATTENUATION
DETECTION
DISTRIBUTION
EIGENSTATES
INFORMATION THEORY
OSCILLATORS
QUANTUM COMPUTERS
QUANTUM CRYPTOGRAPHY
QUANTUM ENTANGLEMENT
QUBITS
TOMOGRAPHY