Combined Quantum and Post-Quantum Security for Earth-Satellite Channels

TL;DR

This paper reports the development and deployment of a real-time quantum key distribution system over Earth-satellite channels, integrating quantum and classical cryptography to enhance security against future quantum attacks.

Contribution

It introduces a novel integrated system combining QKD with classical cryptography, demonstrating real-time operation over satellite channels with optimized error reconciliation.

Findings

Successful real-time QKD over satellite channels

Integration of QKD with AES for post-quantum security

Use of error-reconciliation codes to optimize security and key rate

Abstract

Experimental deployment of quantum communication over Earth-satellite channels opens the way to a secure global quantum Internet. In this work, we present results from a real-time prototype quantum key distribution (QKD) system, which entails the development of optical systems including the encoding of entangled photon pairs, the development of transmitters for quantum signaling through an emulated Earth-satellite channel, and the development of quantum-decoding receivers. A unique aspect of our system is the integration of QKD with existing cryptographic methods to ensure quantum-resistant security, even at low-key rates. In addition, we report the use of specially designed error-reconciliation codes that optimize the security versus key-rate trade-off. Our work demonstrates, for the first time, a deployment of the BBM92 protocol that offers both post-quantum security via the advanced encryption standard (AES) and quantum security via an entanglement-based QKD protocol. If either the AES or the QKD is compromised through some adversary attack, our system still delivers state-of-the-art communications secure against future quantum computers.