Romain Alléaume | LIP6 - Équipe QI

Continuous-variable quantum communication

Tue, 09 Dec 2025 00:00:00 +0000

Tremendous progress in experimental quantum optics during the past decades enabled the advent of quantum technologies, one of which is quantum communication. Aimed at novel methods for more secure or efficient information transfer, quantum communication has developed into an active field of research and proceeds toward full-scale implementations and industrialization. Continuous-variable methods of multi-photon quantum state preparation, manipulation, and coherent detection, as well as the respective theoretical tools of phase-space quantum optics, offer the possibility to make quantum communication efficient, applicable and accessible, thus boosting the development of the field. We review the methodology, techniques and protocols of continuous-variable quantum communication, from the first theoretical ideas, through milestone implementations, to the recent developments, covering quantum key distribution as well as other quantum communication schemes, suggested on the basis of continuous-variable states and measurements.

Quantum Key Distribution with Efficient Post-Quantum Cryptography-Secured Trusted Node on a Quantum Network

Wed, 23 Apr 2025 00:00:00 +0000

Quantum Key Distribution (QKD) enables two distant users to exchange a secret key with information-theoretic security, based on the fundamental laws of quantum physics. While it is arguably the most mature application of quantum cryptography, it has inherent limitations in the achievable distance and the scalability to large-scale infrastructures. While the applicability of QKD can be readily increased with the use of intermediary trusted nodes, this adds additional privacy requirements on third parties. In this work, we present an efficient scheme leveraging a trusted node with lower privacy requirements thanks to the use of post-quantum cryptographic techniques, and implement it on a deployed fiber optic quantum communication network in the Paris area.

Post-Quantum Cryptographically-Secured Trusted Node for Quantum Key Distribution in a Deployed Network

Mon, 02 Sep 2024 00:00:00 +0000

Objective: Reduce the security risks associated with the usage of trusted nodes in a QKD network. Conclusion: The transported QKD key is secure agains honest-curious nodes at a lower key-rate cost than state-of-the-art.

Long-range QKD without trusted nodes is not possible with current technology

Fri, 09 Sep 2022 00:00:00 +0000