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

Research output: Contribution to journalArticlepeer-review

75 Scopus citations


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 down-conversion 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 a 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 a 15% system efficiency.

Original languageEnglish (US)
Article number120506
JournalPhysical review letters
Issue number12
StatePublished - Dec 1 2013
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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