Authors Referees APS Members |
January 2008, to be published in Physical Review A
Continuous-variable quantum key distribution with noisy coherent states
An excess noise in coherent-state preparation can prevent secure key distribution through lossy channel. The feasible single-copy and multi-copy linear optical methods are proposed to purify the prepared state. The single-copy method always sufficiently reduces the excess noise to obtain the key secure against both the individual and collective attacks even through any lossy channel. To increase the secure key rate, two feasible application of the multi-copy linear optical purification are proposed. As a result, maximal secure key rate achievable through a given lossy channel can be approached. © 2008 The American Physical Society.
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