Analysis of the Public Channel of Quantum Key Distribution Link

Authors

• • Miralem Mehic, Department of Telecommunications, VSB-Technical University of Ostrava, Ostrava-Poruba, Czech Republic

• • Oliver Maurhart, Digital Safety and Security Department, AIT Austrian Institute of Technology GmbH, Vienna, Austria

• • Stefan Rass, Universitaet Klagenfurt, Institute of Applied Informatics, System Security Group, Klagenfurt, Austria
  • Dan Komosny, Dept. of Telecommunications, Brno University of Technology, Technicka 3082/12, Brno 61600, Czech Republic
  • Filip Rezac, Department of Telecommunications, VSB-Technical University of Ostrava, Ostrava-Poruba, Czech Republic

• Miroslav Voznak, Department of Telecommunications, VSB-Technical University of Ostrava, Ostrava-Poruba, Czech Republic

Abstract

Quantum Key Distribution (QKD) relies on the laws of physics to establish a symmetric binary key between remote parties. A QKD link involves the realization of a quantum channel for transmission of quantum key material encoded in certain photon properties, as well as a public channel for verification of the exchanged key material. This paper deals with the mutual dependence of these channels and analyzes the impact of performance of both channels on the overall key material establishment process. The work presents measurement data obtained under laboratory conditions as well as the results obtained by establishing a virtual QKD link. Despite the common beliefs that increased quantum bit error rate implies a larger amount of traffic on the public channel, our measurements prove the opposite. The obtained data clearly show that the public channel has a major impact on the overall performance of the QKD link.