Work

Device-Independent Quantum Key Activation

Year: 2025

Type: article

Abstract: Device-independent quantum key distribution (DIQKD) allows two distant parties to establish a secret key, based only on the observed Bell nonlocal distribution. It remains unclear, however, what the minimal resources for enabling DIQKD are and how to maximize the key rate from a given distribution. In the present Letter, we consider a scenario where several copies of a given quantum distribution are jointly processed via a local and classical wiring operation. We find that, under few assumptions, it is possible to activate device-independent key, that is, starting from a distribution that is useless in a DIQKD protocol, we obtain a positive asymptotic key rate by wiring several copies together. We coin this effect device-independent key activation. Our analysis focuses on the standard DIQKD protocol with one-way postprocessing, and we resort to semidefinite programming techniques for computing lower bounds on the key rate.

Source: Physical Review Letters

DOI: 10.1103/f8jc-q1kg

Authors: Bora Ulu, Nicolas Brunner, Mirjam Weilenmann

Institutions: University of Geneva, Télécom Paris, Centre Inria de Saclay, Institut Polytechnique de Paris, Laboratoire Traitement et Communication de l’Information

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Staatssekretariat für Bildung, Forschung und Innovation

Awards: Advantages of adaptive methods for quantum information and quantum foundations, G3504550320, G4430097687