2013/01/31 by Normand J. Beaudry, Marco Lucamarini, Stefano Mancini +1 · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physreva.88.062302
published as Phys. Rev. A 88, 062302 (2013) · 10 pages, 5 figures
arxiv created 2013/12/12 · arxiv updated 2013/12/13
Quantum key distribution protocols typically make use of a one-way quantum channel to distribute a shared secret string to two distant users. However, protocols exploiting a two-way quantum channel have been proposed as an alternative route to the same goal, with the potential advantage of outperforming one-way protocols. Here we provide a strategy to prove security for two-way quantum key distribution protocols against the most general quantum attack possible by an eavesdropper. We utilize an entropic uncertainty relation, and only a few assumptions need to be made about the devices used in the protocol. We also show that a two-way protocol can outperform comparable one-way protocols.