# High-Dimensional Semi-Quantum Cryptography

## TL;DR

This paper introduces a high-dimensional semi-quantum key distribution protocol that enhances noise tolerance and provides a comprehensive security analysis, applicable to various SQKD protocols.

## Contribution

It presents a novel high-dimensional SQKD protocol and general security results that extend to other semi-quantum and standard protocols.

## Key findings

- High-dimensional systems increase noise tolerance in SQKD.
- Security proofs applicable to multiple SQKD protocols.
- Enhanced robustness of semi-quantum key distribution with high-dimensional states.

## Abstract

A semi-quantum key distribution (SQKD) protocol allows two users, one of whom is restricted in their quantum capabilities, to establish a shared secret key, secure against an all-powerful adversary. In this paper, we design a new SQKD protocol using high-dimensional quantum states and conduct an information theoretic security analysis. We show that, similar to the fully-quantum key distribution case, high-dimensional systems can increase the noise tolerance in the semi-quantum case. Along the way, we prove several general security results which are applicable to other SQKD protocols (both high-dimensional ones and standard qubit-based protocols).