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arXiv · 1311.0825

Unconditional Security of Time-energy Entanglement Quantum Key Distribution using Dual-basis Interferometry

Zheshen Zhang·Jacob Mower·Dirk Englund·Franco N. C. Wong·Jeffrey H. Shapiro
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Abstract

High-dimensional quantum key distribution (HDQKD) offers the possibility of high secure-key rate with high photon-information efficiency. We consider HDQKD based on the time-energy entanglement produced by spontaneous parametric downconversion, and show that it is secure against collective attacks. Its security rests upon visibility data -- obtained from Franson and conjugate-Franson interferometers -- that probe photon-pair frequency correlations and arrival-time correlations. From these measurements an upper bound can be established on the eavesdropper's Holevo information by translating the Gaussian-state security analysis for continuous-variable quantum key distribution so that it applies to our protocol. We show that visibility data from just the Franson interferometer provides a weaker, but nonetheless useful, secure-key rate lower bound. To handle multiple-pair emissions, we incorporate the decoy-state approach into our protocol. Our results show that over 200\,km transmission distance in optical fiber, time-energy entanglement HDQKD could permit a 700 bit/sec secure-key rate, and a photon information efficiency of 2 secure-key bits per photon coincidence in the key-generation phase using receivers with 15% system efficiency.

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Zheshen Zhang, Jacob Mower, Dirk Englund, Franco N. C. Wong, Jeffrey H. Shapiro. 2013-11-04. Unconditional Security of Time-energy Entanglement Quantum Key Distribution using Dual-basis Interferometry. https://doi.org/10.1103/physrevlett.112.120506

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