Mutually Unbiased Bases In 3 and 4 Dimensions Semi-quantum Key Distribution Protocol

TL;DR

This paper introduces a semi-quantum key distribution protocol utilizing higher-dimensional systems and mutually unbiased bases, demonstrating increased noise tolerance and higher secret key rates compared to traditional two-level systems.

Contribution

It presents the first security analysis of semi-quantum key distribution protocols based on higher-dimensional systems using mutually unbiased bases.

Findings

Higher-dimensional bases increase noise tolerance.

Derived lower bounds for key rate as a function of noise.

Generalized protocol to four-dimensional states.

Abstract

Semi-quantum key distribution is traditionally based on two-level quantum systems. In this paper, an unconditional security of a semi quantum key distribution protocol based on higher-dimensional systems using various mutually unbiased bases is presented. We first consider the three dimensional case using three and four mutually unbiased bases and derive a lower bound for the key rate as a function of the quantum channel's noise. We then generalize the result to a semi-quantum key distribution protocol that employs different number of mutually unbiased bases for four-dimensional states. It is found that basing the semi-quantum key distribution protocol on higher-dimensional mutually unbiased bases can increase the tolerable threshold of the noise and the maximum achievable value of the secret key rate.