Multidimensional reconciliation for continuous-variable quantum key distribution

Anthony Leverrier (1, 2) , Romain Alleaume (1) , Joseph Boutros (3) , Gilles Zemor (4) , Philippe Grangier (2)

1 ENST - Ecole Nationale Supérieure des Télécommunications
2 Laboratoire Charles Fabry de l'Institut d'Optique / Optique quantique
3 Texas A&M University System
4 IMB - Institut de Mathématiques de Bordeaux

We propose a new method for extracting an errorless secret key in a continuous-variable quantum key distribution protocol, which is based on Gaussian modulation of coherent states and homodyne detection. The crucial novel feature is an eight-dimensional reconciliation method, based on the algebraic properties of octonions. Since the protocol does not use any postselection, it can be proven secure against arbitrary collective attacks, by using well-established theorems on the optimality of Gaussian attacks. By using this new coding scheme with an appropriate signal to noise ratio, the distance for secure continuous-variable quantum key distribution can be significantly extended.

Domaines: Physique Quantique [quant-ph]; Traitement du signal et de l'image [eess.SP]; Traitement du signal et de l'image [eess.SP]

Anthony Leverrier, Romain Alleaume, Joseph Boutros, Gilles Zemor, Philippe Grangier. Multidimensional reconciliation for continuous-variable quantum key distribution. Physical Review A : Atomic, molecular, and optical physics [1990-2015], 2008, 77 (4), pp.042325. ⟨10.1103/PhysRevA.77.042325⟩. ⟨hal-00270517⟩