English
Related papers

Related papers: Computational Complexity of Continuous Variable Qu…

200 papers

We define the direct and reverse secret-key capacities of a memoryless quantum channel as the optimal rates that entanglement-based quantum key distribution protocols can reach by using a single forward classical communication (direct…

Quantum Physics · Physics 2009-02-09 Stefano Pirandola , Raul Garcia-Patron , Samuel L. Braunstein , Seth Lloyd

We present and demonstrate a new protocol for practical quantum cryptography, tailored for an implementation with weak coherent pulses to obtain a high key generation rate. The key is obtained by a simple time-of-arrival measurement on the…

Quantum Physics · Physics 2009-11-11 Damien Stucki , Nicolas Brunner , Nicolas Gisin , Valerio Scarani , Hugo Zbinden

This paper studies the computability of the secrecy capacity of fast-fading wiretap channels from an algorithmic perspective, examining whether it can be computed algorithmically or not. To address this question, the concept of Turing…

Information Theory · Computer Science 2025-01-22 Holger Boche , Andrea Grigorescu , Rafael F. Schaefer , H. Vincent Poor

The field of space communications is the realm of communication technologies where diffraction and atmospheric effects, both of which contribute to loss and noise, become overriding. The pertinent questions here are how and at which rate…

Quantum Physics · Physics 2023-10-27 Masoud Ghalaii , Stefano Pirandola

We consider discrete-modulation protocols for continuous-variable quantum key distribution (CV-QKD) that employ a modulation constellation consisting of a finite number of coherent states and that use a homodyne or a heterodyne-detection…

Quantum Physics · Physics 2021-01-20 Eneet Kaur , Saikat Guha , Mark M. Wilde

The decoy-state method in quantum key distribution (QKD) is a popular technique to approximately achieve the performance of ideal single-photon sources by means of simpler and practical laser sources. In high-speed decoy-state QKD systems,…

Quantum Physics · Physics 2025-04-01 Víctor Zapatero , Álvaro Navarrete , Kiyoshi Tamaki , Marcos Curty

Quantum key distribution, which ensures information-theoretically secret key generation, is currently advancing through photonic integration to achieve high performance, cost reduction and compact size, thereby facilitating the large-scale…

Quantum Physics · Physics 2024-02-19 Yiming Bian , Yan Pan , Xuesong Xu , Liang Zhao , Yang Li , Wei Huang , Lei Zhang , Song Yu , Yichen Zhang , Bingjie Xu

We present a quantum key distribution system with a 2.5 GHz repetition rate using a three-state time-bin protocol combined with a one-decoy approach. Taking advantage of superconducting single-photon detectors optimized for quantum key…

We consider a coded cooperative data exchange problem with the goal of generating a secret key. Specifically, we investigate the number of public transmissions required for a set of clients to agree on a secret key with probability one,…

Information Theory · Computer Science 2014-07-02 Thomas A. Courtade , Thomas R. Halford

Quantum capacity, as the key figure of merit for a given quantum channel, upper bounds the channel's ability in transmitting quantum information. Identifying different type of channels, evaluating the corresponding quantum capacity and…

Quantum Physics · Physics 2023-03-08 Changchun Zhong , Changhun Oh , Liang Jiang

We investigate the performance of several continuous-variable quantum key distribution protocols in the presence of fading channels. These are lossy channels whose transmissivity changes according to a probability distribution. This is…

Quantum Physics · Physics 2018-03-21 Panagiotis Papanastasiou , Christian Weedbrook , Stefano Pirandola

The feasibility of trust-free long-haul quantum key distribution (QKD) networks is addressed. We combine measurement-device-independent QKD (MDI-QKD), as an access technology, with a quantum repeater setup, at the core of future quantum…

Quantum Physics · Physics 2016-03-02 Nicoló Lo Piparo , Mohsen Razavi

In this paper, we present the first experimental demonstration on continuous variable quantum key distribution using determinant Einstein-Podolsky-Rosen entangled states of optical field. By means of the instantaneous measurements of the…

Quantum Physics · Physics 2015-05-30 Xiaolong Su , Wenzhe Wang , Yu Wang , Xiaojun Jia , Changde Xie , Kunchi Peng

Several fundamental issues in establishing security in continuous variable quantum key distribution are discussed, in particular on reverse reconciliation and security under heterodyne attack. It appears difficult to derive quantum…

Quantum Physics · Physics 2016-11-11 Horace P. Yuen

We extend the security proof for continuous variable quantum key distribution protocols using post selection to account for arbitrary eavesdropping attacks by employing the concept of an equivalent protocol where the post-selection is…

Quantum Physics · Physics 2013-03-08 Nathan Walk , Thomas Symul , Ping Koy Lam , Timothy C. Ralph

Quantum key-distribution protocols allow two honest distant parties to establish a common truly random secret key in the presence of powerful adversaries, provided that the two users share beforehand a short secret key. This pre-shared…

Quantum Physics · Physics 2024-01-10 Georgios M. Nikolopoulos , Marc Fischlin

The theory of quantum cryptography aims to guarantee unconditional information-theoretic security against an omnipotent eavesdropper. In many practical scenarios, however, the assumption of an all-powerful adversary is excessive and can be…

We analyse the distribution of secure keys using quantum cryptography based on the continuous variable degree of freedom of entangled photon pairs. We derive the information capacity of a scheme based on the spatial entanglement of photons…

Quantum Physics · Physics 2009-11-13 Lijian Zhang , Christine Silberhorn , Ian A. Walmsley

We propose and demonstrate a fully passive discrete-state continuous-variable quantum key distribution (CV-QKD), which can eliminate all modulator side channels on the source side, using a local local oscillator (LLO). The CV-QKD system…

Quantum Physics · Physics 2026-05-04 Yu Zhang , Xuyang Wang , Chenyang Li , Jie Yun , Qiang Zeng , Zhiliang Yuan , Zhenguo Lu , Yongmin Li

The advent of quantum computers has significantly challenged the security of traditional cryptographic systems, prompting a surge in research on quantum key distribution (QKD). Among various QKD approaches, continuous-variable QKD (CVQKD)…

Quantum Physics · Physics 2025-03-26 Xiaojuan Liao , Yuehan Xu , Qijun Zhang , Peng Huang , Tao Wang , Kaizhi Wang , Guihua Zeng