Universally-composable finite-key analysis for efficient four-intensity decoy-state quantum key distribution

TL;DR

This paper introduces an efficient four-intensity decoy-state BB84 quantum key distribution protocol with universal composability, demonstrating significant improvements in secret key rate over three-intensity protocols, especially at long distances.

Contribution

The paper develops a new four-intensity decoy-state protocol with concise security bounds, enhancing secret key rates compared to existing three-intensity methods.

Findings

Secret key rate increased by at least 30%

Performance improves with longer transmission distances

Protocol maintains security with finite-key analysis

Abstract

We propose an efficient four-intensity decoy-state BB84 protocol and derive concise security bounds for this protocol with the universally composable finite-key analysis method. Comparing with the efficient three-intensity protocol, we find that our efficient four-intensity protocol can increase the secret key rate by at least $30\%$. Particularly, this increasing rate of secret key rate will be raised as the transmission distance increases. At a large transmission distance, our efficient four-intensity protocol can improve the performance of quantum key distribution profoundly.