Increasing Interference Detection in Quantum Cryptography using the Quantum Fourier Transform

TL;DR

This paper introduces two quantum cryptographic protocols utilizing the quantum Fourier transform to enhance eavesdropping detection, especially when attackers measure only a subset of qubits, and offers practical improvements over previous methods.

Contribution

The paper presents novel QFT-based quantum cryptographic protocols that improve eavesdropping detection without requiring quantum memory, and provides analytical tools for customizing detection schemes.

Findings

QFT-based protocols outperform traditional methods in detecting partial measurements.

The proposed QKD protocol is more practical and does not rely on quantum memory.

Equations are provided for analyzing and designing custom QFT-based detection schemes.

Abstract

Quantum key distribution (QKD) and quantum message encryption protocols promise a secure way to distribute information while detecting eavesdropping. However, current protocols may suffer from significantly reduced eavesdropping protection when only a subset of qubits are observed by an attacker. In this paper, we present two quantum cryptographic protocols leveraging the quantum Fourier transform (QFT) and show their higher effectiveness even when an attacker measures only a subset of the transmitted qubits. The foremost of these protocols is a novel QKD method that leverages this effectiveness of the QFT while being more practical than previously proposed QFT-based protocols, most notably by not relying on quantum memory. We additionally show how existing quantum encryption methods can be augmented with a QFT-based approach to improve eavesdropping detection. Finally, we provide equations to analyze different QFT-based detection schemes within these protocols so that protocol designers can make custom schemes for their purpose.