4,244 Hits in 5.5 sec

Efficiency in Quantum Key Distribution Protocols with Entangled Gaussian States

C. Rodó, O. Romero-Isart, K. Eckert, A. Sanpera
2007 Open systems & information dynamics  
Here, we analyze the efficiency of QKD protocols that use as a resource entangled gaussian states and gaussian operations only. In this framework, it has already been shown that QKD is possible (M.  ...  We relate the efficiency of the protocol to the entanglement and purity of the states shared between the parties.  ...  The efficiency of Maurer's protocol, strongly increases with decreasing ǫ AB , and, therefore, the states with higher entanglement will provide a higher key rate.  ... 
doi:10.1007/s11080-007-9030-x fatcat:zzyu7mxtrjfgladuuc42zkbcxe

Efficiency in Quantum Key Distribution Protocols using entangled Gaussian states [article]

Carles Rodó
2010 arXiv   pre-print
We will first show that Quantum Key Distribution is possible with an "Entanglement based" scheme with NPPT symmetric Gaussian states in spite of the fact that these systems cannot be distilled with Gaussian  ...  Efficiency is a key issue in any real implementation of a cryptographic protocol since the physical resources are not unlimited.  ...  in QKD protocols with entangled Gaussian states Efficiency is a key issue in any real implementation of a cryptographic protocol since the physical resources are not unlimited.  ... 
arXiv:1005.2291v2 fatcat:knuhughgindpzpcpvdnac2lmq4

A Survey on Quantum Key Distribution

Laszlo Gyongyosi, Laszlo Bacsardi, Sandor Imre
2019 Infocommunications journal  
Quantum key distribution (QKD) protocols represent an important practical application of quantum information theory.  ...  We review the principles of QKD systems, the implementation basis, and the application of QKD protocols in the standard Internet and the quantum Internet.  ...  Alice draws Gaussian random raw data with Gaussian variables. Using her raw data, she modulates the CV quantum states via a Gaussian modulation.  ... 
doi:10.36244/icj.2019.2.2 fatcat:no7rpoy2uzd2jazrscluzygwei

Efficient entanglement distillation without quantum memory

Daniela Abdelkhalek, Mareike Syllwasschy, Nicolas J. Cerf, Jaromír Fiurášek, Roman Schnabel
2016 Nature Communications  
Since our protocol includes the final measurement it is particularly promising for enhancing continuous-variable quantum key distribution.  ...  Entanglement distribution between distant parties is an essential component to most quantum communication protocols.  ...  The performance of the distillation protocol and its usefulness for quantum key distribution is illustrated in Fig. 3 .  ... 
doi:10.1038/ncomms11720 pmid:27241946 pmcid:PMC4895034 fatcat:pwc3vfuauzcvvla44q47pqoy6i

Long-distance continuous-variable quantum key distribution using separable Gaussian states

Jian Zhou, Duan Huang, Ying Guo
2018 Physical Review A  
In this paper, we present a scheme for implementing long-distance CVQKD using separable Gaussian states.  ...  Continuous-variable quantum key distribution (CVQKD) is considered to be an alternative to classical cryptography for secure communication.  ...  Distributing entanglement with separable states is a breakthrough in the theory of quantum entanglement.  ... 
doi:10.1103/physreva.98.042303 fatcat:4kpaebmic5bchlfhvivfcfk2pe

Stabilization of transmittance fluctuations caused by beam wandering in continuous-variable quantum communication over free-space atmospheric channels

Vladyslav C. Usenko, Christian Peuntinger, Bettina Heim, Kevin Günthner, Ivan Derkach, Dominique Elser, Christoph Marquardt, Radim Filip, Gerd Leuchs
2018 Optics Express  
We also theoretically study the possibility to share an entangled state or to establish secure quantum key distribution over the turbulent atmospheric channels with varying beam widths.  ...  We study the possibility to stabilize the fluctuations by expanding the beam, and test this channel stabilization in regard of continuous-variable entanglement sharing and quantum key distribution.  ...  For Gaussian entanglement distribution or for the coherent-state CV QKD protocol with optimized modulation the method would have been useful for a stronger channel turbulence.  ... 
doi:10.1364/oe.26.031106 fatcat:2ktbd2rnxfcurn4ilff6mwbmoq

Quantum repeater for continuous variable entanglement distribution [article]

Josephine Dias, Matthew S. Winnel, Nedasadat Hosseinidehaj, Timothy C. Ralph
2020 arXiv   pre-print
In this paper, we present an improved continuous variable repeater scheme using optimal Gaussian entanglement swapping. Our scheme uses the noiseless linear amplifier for entanglement distillation.  ...  We show that with the simplest configuration of the noiseless linear amplifier and under the assumption of good quantum memories and perfect sources and detectors, our scheme beats the direct transmission  ...  Entanglement distribution Beginning with entanglement distribution, the entangled resource states used in our protocol are the Gaussian Components of the CV quantum repeater (a) Entanglement distribution  ... 
arXiv:2004.06345v2 fatcat:4xtlrj3545b6pj35ovk3ulad7a

Security of continuous-variable quantum cryptography with Gaussian postselection

Nathan Walk, Timothy C. Ralph, Thomas Symul, Ping Koy Lam
2013 Physical Review A. Atomic, Molecular, and Optical Physics  
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  ...  Finally we explicitly evaluate the performance for the case of a noisy Gaussian channel in the limit of unbounded key length and find improvements over all pre-existing continuous variable protocols in  ...  Quantum key distribution (QKD) is the process of generating a common random key between two parties using a quantum communications protocol.  ... 
doi:10.1103/physreva.87.020303 fatcat:2lwgohgh25cxpawdmto2wosobe

Gaussian postselection and virtual noiseless amplification in continuous-variable quantum key distribution

Jaromír Fiurášek, Nicolas J. Cerf
2012 Physical Review A. Atomic, Molecular, and Optical Physics  
We show that inserting such noiseless operations in a transmission line improves the performance of continuous-variable quantum key distribution over this line.  ...  The noiseless amplification or attenuation are two heralded filtering operations that enable respectively to increase or decrease the mean field of any quantum state of light with no added noise, at the  ...  INTRODUCTION Continuous-variable quantum key distribution (CV QKD) based on Gaussian states and homodyne or heterodyne detection can achieve very high secret key rates; see, e.g., [1] for a review.  ... 
doi:10.1103/physreva.86.060302 fatcat:2nh2opsr2bhghc25ki4zfadg54

CV-QKD with Gaussian and Non-Gaussian Entangled States over Satellite-Based Channels

Nedasadat Hosseinidehaj, Robert Malaney
2016 2016 IEEE Global Communications Conference (GLOBECOM)  
In this work we investigate the effectiveness of continuous-variable (CV) entangled states, transferred through high-loss atmospheric channels, as a means of viable quantum key distribution (QKD) between  ...  In particular, we investigate the role played by the Gaussian CV states as compared to non-Gaussian states.  ...  Thus, it remains unclear whether non-Gaussian entangled states can be effective in the implementation of CV-QKD protocols over atmospheric fading channels (in terms of the quantum key generation rates)  ... 
doi:10.1109/glocom.2016.7841711 dblp:conf/globecom/HosseinidehajM16 fatcat:s7pksgudl5htxfn2zlt5y6jszu

Continuous variable quantum key distribution based on optical entangled states without signal modulation

Xiaolong Su, Wenzhe Wang, Yu Wang, Xiaojun Jia, Changde Xie, Kunchi Peng
2009 Europhysics letters  
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 fluctuations of optical modes respectively distributed at sender and receiver, the random bits of secret key are obtained without the need for  ...  In the EB CV QKD protocols, the quantum fluctuations of entangled optical beams with the truly quantum randomness are utilized to generate the key.  ... 
doi:10.1209/0295-5075/87/20005 fatcat:utkizhc7xrelxnqirda2iiaj3q


2012 International Journal of Modern Physics B  
I.Introduction The history of quantum key distribution protocol started in 1982 [1] in which the secret key was first established by the measurements of single photons.  ...  II.The Protocol: Let us consider a subclass of Gaussian states that plays relevant role in quantum information constituted by symmetric two-mode squeezed thermal states.  ... 
doi:10.1142/s0217979212501093 fatcat:n5n2oeqiurgpddf4eutlv2tijy

Repeaters for continuous-variable quantum communication

Fabian Furrer, William J. Munro
2018 Physical Review A  
the Gaussian character of the final state), but complemented with a heralded non-Gaussian entanglement swapping protocol, which allows us to avoid extensive iterations of quantum Gaussification.  ...  We characterize the performance of this scheme in terms of key rates for quantum key distribution and show a secure key can be generated over thousands of kilometers.  ...  -We gratefully acknowledge useful discussions with Jens Eisert, Akihito Soeda, Koji Azuma and Kiyoshi Tamaki.  ... 
doi:10.1103/physreva.98.032335 fatcat:hqllv5iprvfenpkrcdldjjv4uq

Quantum Information with Continuous Variable systems [article]

Carles Rodó
2011 arXiv   pre-print
This thesis deals with the study of quantum communication protocols with Continuous Variable (CV) systems.  ...  Nevertheless, it is known that in spite of their exceptional role within the space of all Continuous Variable states, in fact, Gaussian states are not always the best candidates to perform quantum information  ...  Thus, in the Gaussian scenario all entangled Quantum Key Distribution with Continuous Variable Gaussian states 49 Gaussian states posses bound entanglement.  ... 
arXiv:1005.4694v2 fatcat:lslgg5erzfgwlkdqrky5pwhome

Non-Markovian Reactivation of Quantum Relays [article]

Stefano Pirandola, Carlo Ottaviani, Christian S. Jacobsen, Gaetana Spedalieri, Samuel L. Braunstein, Tobias Gehring, Ulrik L. Andersen
2015 arXiv   pre-print
We consider a quantum relay which is used by two parties to perform several continuous-variable protocols: Entanglement swapping, distillation, quantum teleportation, and quantum key distribution.  ...  In fact, above a critical amount, these correlations are able to restore the distribution of quadripartite entanglement, which can be localized into an exploitable bipartite form by the action of the relay  ...  P. acknowledges support from the EPSRC via the 'Quantum Communications HUB' (EP/M013472/1) and the grant 'qDATA' (EP/L011298/1). S. P. also thanks the Leverhulme Trust (research fellowship 'qBIO').  ... 
arXiv:1505.07457v1 fatcat:uzgqubsdcrhy3p7hutebc6xp4a
« Previous Showing results 1 — 15 out of 4,244 results