Experimental Decoy State Quantum Key Distribution with Unconditional Security Incorporating Finite Statistics

TL;DR

This paper demonstrates an improved decoy state quantum key distribution method that accounts for finite statistics, achieving a secure key rate of 200 bps over 20 km fiber while maintaining strong security against eavesdroppers.

Contribution

It introduces an enhanced decoy state QKD protocol incorporating finite statistics and experimentally verifies its effectiveness over practical fiber links.

Findings

Achieved a 200 bps key rate over 20 km fiber

Maintained eavesdropper's mutual information below 2^{-9}

Validated the protocol's security with finite statistics considerations

Abstract

We propose the improved decoy state quantum key distribution incorporating finite statistics due to the finite code length and report on its demonstration. In our experiment, four different intensities including the vacuum state for optimal pulses are used and the key generation rate of 200 bps is achieved in the 20 km telecom optical fiber transmission keeping the eavesdropper's mutual information with the final key less than 2^{-9}.