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Experimental Quantum Key Distribution with Decoy States

Yi Zhao·Bing Qi·Xiongfeng Ma·Hoi-Kwong Lo·Li Qian
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Abstract

To increase dramatically the distance and the secure key generation rate of quantum key distribution (QKD), the idea of quantum decoys--signals of different intensities--has recently been proposed. Here, we present the first experimental implementation of decoy state QKD. By making simple modifications to a commercial quantum key distribution system, we show that a secure key generation rate of 165bit/s, which is 1/4 of the theoretical limit, can be obtained over 15km of a Telecom fiber. We also show that with the same experimental parameters, not even a single bit of secure key can be extracted with a non-decoy-state protocol. Compared to building single photon sources, decoy state QKD is a much simpler method for increasing the distance and key generation rate of unconditionally secure QKD.

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Yi Zhao, Bing Qi, Xiongfeng Ma, Hoi-Kwong Lo, Li Qian. 2005-11-03. Experimental Quantum Key Distribution with Decoy States. https://doi.org/10.1103/physrevlett.96.070502

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