Optimization of Secret Key Rate for BB84 under Collective Rotation Noise

TL;DR

This paper analyzes the security of the BB84 quantum key distribution protocol under collective rotation noise, proposing a noise engineering strategy to optimize secret key rate and enhance robustness in realistic noisy channels.

Contribution

It introduces a noise engineering approach that minimizes eavesdropper information while maintaining a high secret key rate under collective rotation noise.

Findings

Collective rotation noise significantly affects shared information and security parameters.

A non-zero noise range exists where Eve's information is minimized with small SKR degradation.

The strategy improves the robustness of BB84 in practical noisy quantum channels.

Abstract

Practical quantum key distribution (QKD) systems operate under noise, but security of most protocols have been analyzed under ideal noiseless scenarios. In this work, we investigated security performance of BB84 protocol under effect of collective rotation noise. Using theoretical quantum information frameworks, we analyzed key security parameters including quantum bit error rate (QBER), mutual information and secret key rate (SKR). Security of protocol is studied under various eavesdropping scenarios based on intercept and resend attacks. Our results show that collective rotation noise has a significant impact on the information shared between the two parties. Particularly, we extended prior treatments by suggesting a noise engineering strategy where we identified a non-zero noise range where information accessed by Eve is minimized while corresponding SKR degradation remains relatively small. This analysis provide insights into robustness of BB84 protocol under realistic noisy channels and may contribute towards development of more resilient QKD systems.