Work

Enhanced simultaneous quantum-classical communications under composable security

Year: 2025

Type: article

Abstract: Simultaneous quantum-classical communications (SQCC) protocols are a family of continuous-variable quantum key distribution (CV-QKD) protocols which allow for quantum and classical symbols to be integrated concurrently on the same optical pulse and mode. In this work, we present a revised analysis of simultaneous quantum-classical communications in Gaussian-modulated coherent-state CV-QKD protocols. We address security concerns inherently associated with SQCC schemes and provide an updated model of the coupling between the classical and quantum channels. We provide evidence for our model via Monte Carlo simulation. We compute the performance of our revised SQCC protocol in terms of the secret-key generation rate optimised over free parameters and demonstrate improved quantum efficiency for a given classical bit-error rate. Lastly, we extend our analysis into the finite-key regime, where we propose a scheme for composably-secure SQCC under realistic operating conditions and demonstrate that our scheme retains the advantage in quantum performance over previous models.

Source: Physical Review A

DOI: 10.1103/p34s-5217

Authors: Nicholas Zaunders, Ziqing Wang, Robert Malaney, Ryan Aguinaldo, Timothy C. Ralph

Institutions: The University of Queensland, UNSW Sydney, Northrop Grumman (United States)

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: green

Funders: Australian Government, Australian Research Council

Awards: A Space-Based Quantum Communications Platform using Continuous Variables, G8272242777