Performance of Quantum Key Distribution Protocol with Dual-Rail Displaced Photon States

TL;DR

This paper introduces a quantum key distribution protocol using dual-rail displaced photon states, which enhances resistance to eavesdropping and is compatible with standard telecommunication systems, even under high attenuation conditions.

Contribution

It proposes a novel QKD scheme utilizing large-amplitude displaced photon states, improving eavesdropping resistance and practical implementation over existing faint laser pulse methods.

Findings

Protocol demonstrates robustness against certain eavesdropping attacks.

Uses large-amplitude pulses to approximate standard telecommunication signals.

Provides a method to estimate information leakage based on output distribution comparison.

Abstract

We propose a scheme for quantum key distribution (QKD) protocol with dual-rail displaced photon states. Displaced single photon states carry bit value of code which may be extracted while coherent states carry nothing and they only provide inconclusive outcome. Developed QKD protocol works with experimental attendant noise to observe presence of malicious Eve. Pulses with large amplitudes unlike conventional QKD relying on faint laser pulses are used that may approximate it to standard telecommunication communication and may show resistance to eavesdropping even in settings with high attenuation. Information leakage to the eavesdropper is determined from comparison of output distribution of the outcomes with ideal one that is defined by two additional inaccessible to nobody, saving for who sends the pulses, parameters. Robustness to some possible eavesdropping attacks is shown.