2015/09/30 by L. C. Comandar, M. Lucamarini, B. Fröhlich +6 · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1038/nphoton.2016.50
published as Nature Photonics 10, 312-315 (2016) · 11 pages, 3 figures, 1 table. Supplementary information included. Citation typo in the abstract corrected
arxiv created 2015/10/01 · arxiv updated 2018/01/11
Security in quantum cryptography is continuously challenged by inventive attacks targeting the real components of a cryptographic setup, and duly restored by new counter-measures to foil them. Due to their high sensitivity and complex design, detectors are the most frequently attacked components. Recently it was shown that two-photon interference from independent light sources can be exploited to avoid the use of detectors at the two ends of the communication channel. This new form of detection-safe quantum cryptography, called Measurement-Device-Independent Quantum Key Distribution (MDI-QKD), has been experimentally demonstrated, but with modest delivered key rates. Here we introduce a novel pulsed laser seeding technique to obtain high-visibility interference from gain-switched lasers and thereby perform quantum cryptography without detector vulnerabilities with unprecedented bit rates, in excess of 1 Mb/s. This represents a 2 to 6 orders of magnitude improvement over existing implementations and for the first time promotes the new scheme as a practical resource for quantum secure communications.