Quantum cryptography using partially entangled states

TL;DR

This paper demonstrates that partially entangled states can be effectively used in quantum key distribution protocols, offering comparable security and key rates to standard methods, with added control features.

Contribution

It introduces a novel QKD scheme utilizing non-maximally entangled states and a controllable parameter for security and key rate optimization.

Findings

Nearly equivalent security to standard QKD protocols

A controllable parameter for security and key rate adjustment

A scheme enabling a third party to control key sharing

Abstract

We show that non-maximally entangled states can be used to build a quantum key distribution (QKD) scheme whose security and key rate transmission is nearly equivalent to those of standard QKD protocols. These aspects can be controlled by using the new free parameter in the present scheme, namely, the degree of partial entanglement. Furthermore, we discuss how to build a controlled QKD scheme, also based on partially entangled states, where a third party can decide whether or not Alice and Bob are allowed to share a key.