# Quantum key distribution over 122 km of standard telecom fiber

@article{Gobby2004QuantumKD, title={Quantum key distribution over 122 km of standard telecom fiber}, author={C. Gobby and Z. L. Yuan and Andrew J. Shields}, journal={Applied Physics Letters}, year={2004}, volume={84}, pages={3762-3764} }

We report a demonstration of quantum key distribution over a standard telecom fiber exceeding 100 km in length. Through careful optimization of the interferometer and single photon detector, we achieve a quantum bit error ratio of 8.9% for a 122 km link, allowing a secure shared key to be formed after error correction and privacy amplification. Key formation rates of up to 1.9 kbit/s are achieved depending upon fiber length. We discuss the factors limiting the maximum fiber length in quantum…

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