2011/03/31 by Nitin Jain, Christoffer Wittmann, Lars Lydersen +5 · 2 citations
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physrevlett.107.110501
published as Physical Review Letters 107, 110501 (2011) · 4 pages + 1 page of supplementary information. Considerable modification of Eve's attack strategy and QBER minimization technique. All figures have also been improved
arxiv created 2011/09/16 · arxiv updated 2011/09/19
Characterizing the physical channel and calibrating the cryptosystem hardware are prerequisites for establishing a quantum channel for quantum key distribution (QKD). Moreover, an inappropriately implemented calibration routine can open a fatal security loophole. We propose and experimentally demonstrate a method to induce a large temporal detector efficiency mismatch in a commercial QKD system by deceiving a channel length calibration routine. We then devise an optimal and realistic strategy using faked states to break the security of the cryptosystem. A fix for this loophole is also suggested.