Authors:
Ágoston Schranz
and
Eszter Udvary
Affiliation:
Department of Broadband Infocommunications and Electromagnetic Theory, Budapest University of Technology and Economics, Egry József utca 18., Budapest and Hungary
Keyword(s):
Quantum Key Distribution (QKD), BB84, Polarization Switching, Polarization Rotation, Quantum Bit Error Rate (QBER).
Related
Ontology
Subjects/Areas/Topics:
Lasers
;
Photonics, Optics and Laser Technology
;
Quantum Information and Measurement
;
Semiconductor Lasers and Leds
Abstract:
In the BB84 quantum key distribution (QKD) protocol, the communicating parties do a quantum bit error rate (QBER) test to determine whether there is an eavesdropper trying to gain information about the secret key. However, the QBER is not only influenced by the eavesdropper’s strategies, but also by the imperfections of the physical devices and the channel through which the quantum states propagate. We developed a simple channel model with error parameters describing the channel and the potential polarization switching in the transmitter, to see how those effects influence the QBER in a polarization-qubit BB84 implementation. Certain well-defined probabilistic channel models are compared to see which is responsible for the highest error probability.