Finite-size analysis of a continuous-variable quantum key distribution

Anthony Leverrier (1) , Frédéric Grosshans (2) , Philippe Grangier (3)

1 LTCI - Laboratoire Traitement et Communication de l'Information
2 LPQM - Laboratoire de Photonique Quantique et Moléculaire
3 Laboratoire Charles Fabry de l'Institut d'Optique / Optique quantique

The goal of this paper is to extend the framework of finite size analysis recently developed for quantum key distribution to continuous-variable protocols. We do not solve this problem completely here, and we mainly consider the finite size effects on the parameter estimation procedure. Despite the fact that some questions are left open, we are able to give an estimation of the secret key rate for protocols which do not contain a postselection procedure. As expected, these results are significantly more pessimistic than the ones obtained in the asymptotic regime. However, we show that recent continuous-variable protocols are able to provide fully secure secret keys in the finite size scenario, over distances larger than 50 km.

Domains: Quantum Physics [quant-ph]

Anthony Leverrier, Frédéric Grosshans, Philippe Grangier. Finite-size analysis of a continuous-variable quantum key distribution. Physical Review A : Atomic, molecular, and optical physics [1990-2015], 2010, 81, pp.062343. ⟨10.1103/PhysRevA.81.062343⟩. ⟨hal-00553554⟩