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Electronics Letters

Operational system for quantum cryptography

J. D. Franson, B. C. Jacobs

Published Feb 2, 1995• 67 citations
Publisher

Abstract

An operational system for quantum cryptography based on the polarisations of single photons has been demonstrated. The system allows the automated transmission of secure messages between two computers at data rates up to 5 kHz with lower error rates than previous systems.
DOI
10.1049/el:19950153

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Pioneering experiments on single-photon quantum cryptography that are performed with a tailored setup are reported. The key is transferred by pulsed semiconductor lasers, which encode the polarization state of the photons in two mutually nonorthogonal bases. Photon detectors are based on C30902S silicon avalanche photodiodes. For a laser pulse repetition rate of 100 kHz and a mean number of photons per pulse of about 0.2, the key generation rate reaches ≈4 kbit/s. The error rate in the key does not exceed 1%.
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