English
Related papers

Related papers: Getting Something Out of Nothing

200 papers

Quantum key distribution (QKD) is a provably secure way of generating a secret key, which can later be used for encoding and decoding information. In this paper we analyze the effects of an eavesdropper's variable-strength measurements on…

Quantum Physics · Physics 2025-10-01 Yuval Idan , Tal Gofman , Ziv Abelson , Isabelle Cestier , Elad Mentovich , Eliahu Cohen

Quantum computers promise significant speedups in solving problems intractable for conventional computers but, despite recent progress, remain limited in scaling and availability. Therefore, quantum software and hardware development heavily…

Quantum Physics · Physics 2023-11-08 Stefan Hillmich , Igor L. Markov , Robert Wille

We present a general theorem for the efficient verification of the lower bound of single-photon transmittance. We show how to do decoy-state quantum key distribution efficiently with large random errors in the intensity control. In our…

Quantum Physics · Physics 2009-11-13 X. B. Wang

In this study, we analyze the efficiency of a protocol with discrete modulation of continuous variable non-Gaussian states, the coherent states having one photon added and then one photon subtracted (PASCS). We calculate the secure key…

Quantum Physics · Physics 2022-11-01 L. S. Aguiar , L. F. M. Borelli , J. A. Roversi , A. Vidiella-Barranco

The malicious manipulation of quantum key distribution (QKD) hardware is a serious threat to its security, as, typically, neither end users nor QKD manufacturers can validate the integrity of every component of their QKD system in practice.…

Quantum Physics · Physics 2025-04-01 Víctor Zapatero , Marcos Curty

Measuring quantum states provides means to generate genuine random numbers. It has been shown that genuine randomness can be obtained even with an uncharacterized quantum source. In this work, we propose a framework that formalizes the idea…

Quantum Physics · Physics 2019-05-23 Jiajun Ma , Xiao Yuan , Aishwarya Hakande , Xiongfeng Ma

Modern security proofs of quantum key distribution (QKD) must take finite-size effects and composable aspects into consideration. This is also the case for continuous-variable (CV) protocols which are based on the transmission and detection…

Quantum Physics · Physics 2025-11-27 Stefano Pirandola , Panagiotis Papanastasiou

We investigate a decoy-state quantum key distribution (QKD) scheme with a sub-Poissonian single-photon source, which is generated on demand by scattering a coherent state off a two-level system in a one-dimensional waveguide. We show that,…

Quantum Physics · Physics 2013-02-22 Huaixiu Zheng , Daniel J. Gauthier , Harold U. Baranger

Quantum cryptography is a major ingredient of the future quantum internet that promises various secure communication tasks. Quantum conference key agreement (CKA) is an important cryptographic primitive of quantum cryptography, which…

Quantum Physics · Physics 2021-09-28 Xiao-Yu Cao , Yu-shuo Lu , Zhao Li , Jie Gu , Hua-Lei Yin , Zeng-Bing Chen

We propose an efficient quantum key distribution protocol based on the photon-pair generation from parametric down-conversion (PDC). It uses the same experimental setup as the conventional protocol, but a refined data analysis enables…

Quantum Physics · Physics 2009-11-13 Yoritoshi Adachi , Takashi Yamamoto , Masato Koashi , Nobuyuki Imoto

Quantum key distribution (QKD) offers the promise of absolutely secure communications. However, proofs of absolute security often assume perfect implementation from theory to experiment. Thus, existing systems may be prone to insidious…

Quantum Physics · Physics 2014-06-23 Samuel L. Braunstein , Stefano Pirandola

Continuous variable quantum key distribution (CVQKD) with discrete modulation combines advantages of CVQKD, such as the implementability using readily available technologies, with advantages of discrete variable quantum key distribution,…

Quantum Physics · Physics 2025-02-13 Carlos Pascual-García , Stefan Bäuml , Mateus Araújo , Rotem Liss , Antonio Acín

We investigate the security against collective attacks of a continuous variable quantum key distribution scheme in the asymptotic key limit for a realistic setting. The quantum channel connecting the two honest parties is assumed to be…

Quantum Physics · Physics 2007-12-12 Matthias Heid , Norbert Lütkenhaus

It is shown that the basic equations of quantum theory can be obtained from a straightforward application of logical inference to experiments for which there is uncertainty about individual events and for which the frequencies of the…

Quantum Physics · Physics 2014-06-03 H. De Raedt , M. I. Katsnelson , K. Michielsen

Continuous variable (CV) quantum key distribution (QKD) provides a powerful setting for secure quantum communications, thanks to the use of room-temperature off-the-shelf optical devices and the potential to reach much higher rates than the…

Quantum Physics · Physics 2022-03-03 Stefano Pirandola

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

Quantum Key Distribution is a quantum communication technique in which random numbers are encoded on quantum systems, usually photons, and sent from one party, Alice, to another, Bob. Using the data sent via the quantum signals,…

Quantum Physics · Physics 2014-09-09 T. C. Ralph , N. Walk

Quantum key distribution---exchanging a random secret key relying on a quantum mechanical resource---is the core feature of secure quantum networks. Entanglement-based protocols offer additional layers of security and scale favorably with…

A new and simple quantum key distribution scheme based on the quantum intensity correlation of optical twin beams and the directly local measurements of intensity noise of single optical beam is presented and experimentally demonstrated.…

Quantum Physics · Physics 2007-05-23 Xiaojun Jia , Xiaolong Su , Qing Pan , Kunchi Peng , Changde Xie

We demonstrate that a necessary precondition for unconditionally secure quantum key distribution is that sender and receiver can use the available measurement results to prove the presence of entanglement in a quantum state that is…

Quantum Physics · Physics 2009-11-10 Marcos Curty , Maciej Lewenstein , Norbert Lütkenhaus