We describe a free space quantum cryptography system which is designed to allow continuous unattended key exchanges for periods of several days, and over ranges of a few kilometres. The system uses a four-laser faint-pulse transmission system running at a pulse rate of 10MHz to generate the required four alternative polarization states. The receiver module similarly automatically selects a measurement basis and performs polarization measurements with four avalanche photodiodes. The controlling software can implement the full key exchange including sifting, error correction, and privacy amplification required to generate a secure key.
|Title of host publication||Quantum information and computation III|
|Editors||Eric J. Donkor, Andrew R. Pirich, Howard E. Brandt|
|Number of pages||4|
|Publication status||Published - 1 Jan 2005|
|Event||Quantum Information and Computation III - Orlando, FL, United States|
Duration: 28 Mar 2005 → …
|Conference||Quantum Information and Computation III|
|Period||28/03/05 → …|
Bibliographical noteP. R. Tapster ; P. M. Gorman ; D. M. Benton ; D. M. Taylor and B. S. Lowans, "Developments towards practical free-space quantum cryptography", Proc. SPIE 5815, Quantum Information and Computation III, 176 (June 02, 2005).
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