Quantum Key Recycling can share key more efficient than BB84

TL;DR

This paper introduces a new way to measure key sharing efficiency, showing that Lu et al.'s Quantum Key Recycling protocol can outperform BB84 in certain scenarios, highlighting potential advantages of pre-shared keys.

Contribution

It defines the key sharing rate for both QKD and QKR protocols and compares their efficiencies, demonstrating the potential of QKR to be more resource-efficient than BB84.

Findings

QKR protocol can share keys more efficiently than BB84 in some situations

The six-state QKR protocol outperforms the six-state QKD protocol in key sharing rate

Pre-shared keys can potentially replace public discussion in quantum protocols

Abstract

We calculate the key sharing rate of Lu et al.'s Quantum Key Recycling (QKR) protocol. The key sharing rate is another version of the key rate, but it can be calculated for both the Quantum Key Distribution (QKD) protocols and the QKR protocols. We define the key sharing rate in this study and compare the key sharing rate of the QKR protocol to the rate of the QKD protocols. We found Lu et al.'s QKR protocol can be used to share keys more efficiently than BB84 in some situations. We also compare the six-state version of Lu et al.'s QKR protocol to the six-state QKD protocol. The results of this study show the potential advantages of using pre-shared keys to replace the public discussion in quantum protocols.