English
Related papers

Related papers: Finding and breaking the realistic rate-distance l…

200 papers

Quantum key distribution provides secure keys resistant to code-breaking quantum computers. The continuous-variable version of quantum key distribution offers the advantages of higher secret key rates in metropolitan areas, as well as the…

Continuous-Variable Quantum Key Distribution (CVQKD) at large distances has such high noise levels that the error-correcting code must have very low rate. In this regime it becomes feasible to implement random-codebook error correction,…

Quantum Physics · Physics 2025-11-25 Arpan Akash Ray , Boris Skoric

We compare the effect of different noise scenarios on the achievable rate of an epsilon-secure key for the BB84 and the six-state protocol. We study the situation where quantum noise is added deliberately, and investigate the remarkable…

Quantum Physics · Physics 2015-06-03 Markus Mertz , Hermann Kampermann , Zahra Shadman , Dagmar Bruß

Currently most progresses on quantum secret sharing suffer from rate-distance bound, and thus the key rates are limited. In addition to the limited key rate, the technical difficulty and the corresponding cost together prevent large-scale…

Quantum Physics · Physics 2023-10-09 Chen-Long Li , Yao Fu , Wen-Bo Liu , Yuan-Mei Xie , Bing-Hong Li , Min-Gang Zhou , Hua-Lei Yin , Zeng-Bing Chen

We experimentally demonstrated a sub-Mbps key rate Gaussian-modulated coherent-state continuous-variable quantum key distribution (CV-QKD) over 100 km transmission distance. To efficiently control the excess noise, the quantum signal and…

Quantum Physics · Physics 2023-04-12 Yaodi Pi , Heng Wang , Yan Pan , Yun Shao , Yang Li , Jie Yang , Yichen Zhang , Wei Huang , Bingjie Xu

We provide a simple method to obtain an upper bound on the secret key rate that is particularly suited to analyze practical realizations of quantum key distribution protocols with imperfect devices. We consider the so-called trusted device…

Quantum Physics · Physics 2009-11-11 Tobias Moroder , Marcos Curty , Norbert Lütkenhaus

We present a discretely modulated continuous-variable quantum key distribution system in free space by using strong coherent states. The amplitude noise in the laser source is suppressed to the shot-noise limit by using a mode cleaner…

Quantum Physics · Physics 2015-05-18 Yong Shen , Hongxin Zou , Liang Tian , Pingxing Chen , Jianmin Yuan

The assumption that detection and/or state-preparation devices used for continuous-variable quantum key distribution (CV-QKD) are beyond influence of potential eavesdroppers leads to a significant performance enhancement in terms of…

Quantum Physics · Physics 2019-08-30 Fabian Laudenbach , Christoph Pacher

Quantum key distribution (QKD) enables information-theoretic secure communication, yet its ultimate tolerance to noise and achievable transmission distance remain fundamentally constrained. We establish the maximum quantum bit error rate…

Quantum Physics · Physics 2026-02-27 Stefano Pirandola

We investigate the main limitations which prevent the continuous-variable quantum key distribution protocols from achieving long distances in the finite-size setting. We propose a double-modulation protocol which allows using each state for…

Quantum Physics · Physics 2014-12-22 László Ruppert , Vladyslav C. Usenko , Radim Filip

Quantum key distribution (QKD) enables two remote parties to grow a shared key which they can use for unconditionally secure communication [1]. The applicable distance of a QKD protocol depends on the loss and the excess noise of the…

Quantum Physics · Physics 2012-10-08 Lars S. Madsen , Vladyslav C. Usenko , Mikael Lassen , Radim Filip , Ulrik L. Andersen

We study a practical method to measure the shot noise in real time in Continuous Variable Quantum Key Distribution (CVQKD) systems. The amount of secret key that can be extracted from the raw statistics depends strongly on this quantity…

Quantum Physics · Physics 2015-02-13 Sébastien Kunz-Jacques , Paul Jouguet

We have developed a method to calculate a secret key rate of a continuous-variable quantum-key-distribution scheme using four coherent states and postselection for a general model of Gaussian attacks. We assume that the transmission line…

Quantum Physics · Physics 2018-10-30 Ryo Namiki , Akira Kitagawa , Takuya Hirano

Since 1984, various optical quantum key distribution (QKD) protocols have been proposed and examined. In all of them, the rate of secret key generation decays exponentially with distance. A natural and fundamental question is then whether…

Quantum Physics · Physics 2016-03-29 Masahiro Takeoka , Saikat Guha , Mark M. Wilde

We describe a continuous variables coherent states quantum key distribution system working at 1550 nm, and entirely made of standard fiber optics and telecom components, such as integrated-optics modulators, couplers and fast InGaAs…

Quantum Physics · Physics 2007-05-23 Jérôme Lodewyck , Thierry Debuisschert , Rosa Tualle-Brouri , Philippe Grangier

In this paper we present a new proof technique for semi-quantum key distribution protocols which makes use of a quantum entropic uncertainty relation to bound an adversary's information. Our new technique provides a more optimistic key-rate…

Quantum Physics · Physics 2018-01-09 Walter O. Krawec

Quantum key distribution (QKD) enables two remote parties to share encryption keys with security based on the laws of physics. Continuous variable (CV) QKD with coherent states and coherent detection integrates well with existing…

A realistic Quantum Key Distribution (QKD) protocol necessarily deals with finite resources, such as the number of signals exchanged by the two parties. We derive a bound on the secret key rate which is expressed as an optimization problem…

Quantum Physics · Physics 2011-10-13 Silvestre Abruzzo , Hermann Kampermann , Markus Mertz , Dagmar Bruß

Existing experimental implementations of continuous-variable quantum key distribution require shot-noise limited operation, achieved with shot-noise limited lasers. However, loosening this requirement on the laser source would allow for…

Quantum Physics · Physics 2016-09-22 Christian S. Jacobsen , Tobias Gehring , Ulrik L. Andersen

We address the security of continuous-variable quantum key distribution with squeezed states upon realistic conditions of noisy and lossy environment and limited reconciliation efficiency. Considering the generalized preparation scheme and…

Quantum Physics · Physics 2011-11-10 Vladyslav C. Usenko , Radim Filip
‹ Prev 1 2 3 10 Next ›