Quantum key distribution over 25 km using a fibre set-up based on continuous variables

2007 ◽  
Vol 32 (2-3) ◽  
pp. 163-165
Author(s):  
J. Lodewyck ◽  
M. Bloch ◽  
S. Fossier ◽  
E. Diamanti ◽  
T. Debuisschert ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Continuous Variables ◽  
Set Up

Implementation of continuous variable quantum cryptography in optical fibres using a go-&-return configuration

2006 ◽  
Vol 6 (4&5) ◽  
pp. 326-335
Author(s):  
M. Legré ◽  
H. Zbinden ◽  
N. Gisin
Keyword(s):  
Quantum Cryptography ◽  
Quantum Key Distribution ◽  
Key Distribution ◽  
Continuous Variable ◽  
Optical Fibres ◽  
Continuous Variables ◽  
Phase Fluctuations ◽  
Degree Of Stability ◽  
Set Up ◽  
High Degree

We demonstrate an implementation of quantum key distribution with continuous variables based on a go-&-return configuration over distances up to 14km. This configuration leads to self-compensation of polarisation and phase fluctuations. We observe a high degree of stability of our set-up over many hours.

Quantum key distribution with continuous variables

2001 ◽  
Vol 48 (13) ◽  
pp. 1903-1920 ◽  
Author(s):  
K. Bencheikh ◽  
Th. Symul ◽  
A. Jankovic ◽  
J. A. Levenson
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Continuous Variables

scholarly journals CONTINUOUS VARIABLE QUANTUM KEY DISTRIBUTION USING POLARIZED COHERENT STATES

2006 ◽  
Vol 20 (11n13) ◽  
pp. 1287-1296 ◽  
Author(s):  
A. VIDIELLA-BARRANCO ◽  
L. F. M. BORELLI
Keyword(s):  
Quantum Key Distribution ◽  
Coherent States ◽  
Key Distribution ◽  
Continuous Variable ◽  
Stokes Parameters ◽  
Continuous Variables ◽  
Commuting Operators ◽  
Incoming Beam ◽  
Ideal Situation ◽  
Quantum Counterpart

We discuss a continuous variables method of quantum key distribution employing strongly polarized coherent states of light. The key encoding is performed using the variables known as Stokes parameters, rather than the field quadratures. Their quantum counterpart, the Stokes operators Ŝi ( i =1,2,3), constitute a set of non-commuting operators, being the precision of simultaneous measurements of a pair of them limited by an uncertainty-like relation. Alice transmits a conveniently modulated two-mode coherent state, and Bob randomly measures one of the Stokes parameters of the incoming beam. After performing reconciliation and privacy amplification procedures, it is possible to distill a secret common key. We also consider a non-ideal situation, in which coherent states with thermal noise, instead of pure coherent states, are used for encoding.

scholarly journals Impact of receiver imbalances on the security of continuous variables quantum key distribution

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Daniel Pereira ◽  
Margarida Almeida ◽  
Margarida Facão ◽  
Armando N. Pinto ◽  
Nuno A. Silva
Keyword(s):  
Communication Network ◽  
Quantum Key Distribution ◽  
Key Distribution ◽  
Continuous Variable ◽  
Continuous Variables ◽  
Security Risk ◽  
Channel Parameters ◽  
The Impact

AbstractContinuous-variable quantum key distribution (CV-QKD) provides a theoretical unconditionally secure solution to distribute symmetric keys among users in a communication network. However, the practical devices used to implement these systems are intrinsically imperfect, and, as a result, open the door to eavesdropper attacks. In this work, we show the impact of receiver device imperfections on the estimated channel parameters, performance and security of a CV-QKD system. The presented results show that, due to the erroneously estimated channel parameters, non-monitored imbalances can pose a security risk or even reduce the system’s performance. Our results show the importance of monitoring these imbalances and hint at the possibility of compensating for some receiver imbalances by tuning other components.

scholarly journals Improving Eight-State Continuous Variable Quantum Key Distribution by Applying Photon Subtraction

2019 ◽  
Vol 9 (7) ◽  
pp. 1333 ◽  
Author(s):  
Qingquan Peng ◽  
Xiaodong Wu ◽  
Ying Guo
Keyword(s):  
Quantum Key Distribution ◽  
Single Photon ◽  
Key Distribution ◽  
Continuous Variable ◽  
Quantum States ◽  
Continuous Variables ◽  
Subtraction Method ◽  
Photon Subtraction ◽  
Channel Loss ◽  
Simulation Results

We propose a new method to effectively improve the performance of a quantum key distribution with eight-state continuous variables by the photon subtraction method. This operation is effective in increasing and distilling Gaussian entanglement between quantum states, and can be easily realized by existing technology. Simulation results show that the channel-loss tolerance of the eight-state continuous variable quantum key distribution (CVQKD) protocol can be extended by the appropriate photon subtraction algorithm; namely, single-photon subtraction.

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