The Experts below are selected from a list of 479037 Experts worldwide ranked by ideXlab platform
Philippe Grangier - One of the best experts on this subject based on the ideXlab platform.
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Field test of a continuous-variable quantum Key Distribution prototype
New Journal of Physics, 2009Co-Authors: Simon Fossier, Elisavet Diamanti, Thierry Debuisschert, Rosa Tualle-brouri, Rosa Tuallebrouri, Andre Villing, Philippe GrangierAbstract:We have designed and realized a prototype that implements a continuous-variable quantum Key Distribution protocol based on coherent states and reverse reconciliation. The system uses time and polarization multiplexing for optimal transmission and detection of the signal and phase reference, and employs sophisticated error-correction codes for reconciliation. The security of the system is guaranteed against general coherent eavesdropping attacks. The performance of the prototype was tested over preinstalled optical fibres as part of a quantum cryptography network combining different quantum Key Distribution technologies. The stable and automatic operation of the prototype over 57 hours yielded an average secret Key Distribution rate of 8 kbit/s over a 3 dB loss optical fibre, including the Key extraction process and all quantum and classical communication. This system is therefore ideal for securing communications in metropolitan size networks with high speed requirements.
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multidimensional reconciliation for a continuous variable quantum Key Distribution
Physical Review A, 2008Co-Authors: Anthony Leverrier, Joseph J. Boutros, Romain Alleaume, Gilles Zemor, Philippe GrangierAbstract:We propose a method for extracting an errorless secret Key in a continuous-variable quantum Key Distribution protocol, which is based on Gaussian modulation of coherent states and homodyne detection. The crucial feature is an eight-dimensional reconciliation method based on the algebraic properties of octonions. Since the protocol does not use any post-selection, it can be proven secure against arbitrary collective attacks by using well-established theorems on the optimality of Gaussian attacks. By using this coding scheme with an appropriate signal-to-noise ratio, the distance for a secure continuous-variable quantum Key Distribution can be significantly extended.
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Multidimensional reconciliation for continuous-variable quantum Key Distribution
Physical Review A, 2008Co-Authors: Anthony Leverrier, Romain Alleaume, Gilles Zemor, Joseph Boutros, Philippe GrangierAbstract:We propose a new method for extracting an errorless secret Key in a continuous-variable quantum Key Distribution protocol, which is based on Gaussian modulation of coherent states and homodyne detection. The crucial novel feature is an eight-dimensional reconciliation method, based on the algebraic properties of octonions. Since the protocol does not use any postselection, it can be proven secure against arbitrary collective attacks, by using well-established theorems on the optimality of Gaussian attacks. By using this new coding scheme with an appropriate signal to noise ratio, the distance for secure continuous-variable quantum Key Distribution can be significantly extended.
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SECOQC White Paper on Quantum Key Distribution and Cryptography
arXiv preprint quant-ph 0701168, 2007Co-Authors: Romain Alleaume, Mark Godfrey, Thierry Debuisschert, Cyril Branciard, Jan Bouda, Nicolas Gisin, Thomas Langer, Philippe Grangier, Mehrdad Dianati, Anthony LeverrierAbstract:The SECOQC White Paper on Quantum Key Distribution and Cryptography is the outcome on a thorough consultation and discussion among the participants of the European project SECOQC (www.secoqc.net). This paper is a review article that attempts to position Quantum Key Distribution (QKD) in terms of cryptographic applications. A detailed comparison of QKD with the solutions currently in use to solve the Key Distribution problem, based on classical cryptography, is provided. We also detail how the work on QKD networks lead within SECOQC will allow the deployment of long-distance secure communication infrastructures based on quantum cryptography. The purpose of the White Paper is finally to promote closer collaboration between classical and quantum cryptographers. We believe that very fruitful research, involving both communities, could emerge in the future years and try to sketch what may be the next challenges in this direction.
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quantum cloning and Key Distribution with continuous variables
2005Co-Authors: Nicolas Cerf, Philippe GrangierAbstract:Quantum information with continuous variables is a paradigm which has attracted a growing interest lately, as a consequence of the prospect for high-rate quantum communication systems that may result from the use of standard telecommunication components. After introducing the concept of quantum continuous variables in optics, we turn to the fundamental impossibility of cloning continuous-variable light states, a result which is at the heart of quantum Key Distribution. We then present state-of-the-art quantum Key Distribution systems relying on continuous variables, with a special emphasis on the experimental demonstration of protocols using coherent light states. Finally, we briefly review the recent security proofs of these cryptographic protocols.
Anthony Leverrier - One of the best experts on this subject based on the ideXlab platform.
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multidimensional reconciliation for a continuous variable quantum Key Distribution
Physical Review A, 2008Co-Authors: Anthony Leverrier, Joseph J. Boutros, Romain Alleaume, Gilles Zemor, Philippe GrangierAbstract:We propose a method for extracting an errorless secret Key in a continuous-variable quantum Key Distribution protocol, which is based on Gaussian modulation of coherent states and homodyne detection. The crucial feature is an eight-dimensional reconciliation method based on the algebraic properties of octonions. Since the protocol does not use any post-selection, it can be proven secure against arbitrary collective attacks by using well-established theorems on the optimality of Gaussian attacks. By using this coding scheme with an appropriate signal-to-noise ratio, the distance for a secure continuous-variable quantum Key Distribution can be significantly extended.
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Multidimensional reconciliation for continuous-variable quantum Key Distribution
Physical Review A, 2008Co-Authors: Anthony Leverrier, Romain Alleaume, Gilles Zemor, Joseph Boutros, Philippe GrangierAbstract:We propose a new method for extracting an errorless secret Key in a continuous-variable quantum Key Distribution protocol, which is based on Gaussian modulation of coherent states and homodyne detection. The crucial novel feature is an eight-dimensional reconciliation method, based on the algebraic properties of octonions. Since the protocol does not use any postselection, it can be proven secure against arbitrary collective attacks, by using well-established theorems on the optimality of Gaussian attacks. By using this new coding scheme with an appropriate signal to noise ratio, the distance for secure continuous-variable quantum Key Distribution can be significantly extended.
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SECOQC White Paper on Quantum Key Distribution and Cryptography
arXiv preprint quant-ph 0701168, 2007Co-Authors: Romain Alleaume, Mark Godfrey, Thierry Debuisschert, Cyril Branciard, Jan Bouda, Nicolas Gisin, Thomas Langer, Philippe Grangier, Mehrdad Dianati, Anthony LeverrierAbstract:The SECOQC White Paper on Quantum Key Distribution and Cryptography is the outcome on a thorough consultation and discussion among the participants of the European project SECOQC (www.secoqc.net). This paper is a review article that attempts to position Quantum Key Distribution (QKD) in terms of cryptographic applications. A detailed comparison of QKD with the solutions currently in use to solve the Key Distribution problem, based on classical cryptography, is provided. We also detail how the work on QKD networks lead within SECOQC will allow the deployment of long-distance secure communication infrastructures based on quantum cryptography. The purpose of the White Paper is finally to promote closer collaboration between classical and quantum cryptographers. We believe that very fruitful research, involving both communities, could emerge in the future years and try to sketch what may be the next challenges in this direction.
Norbert Lutkenhaus - One of the best experts on this subject based on the ideXlab platform.
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detector decoy quantum Key Distribution
New Journal of Physics, 2009Co-Authors: Marcos Curty, Norbert Lutkenhaus, Tobias MoroderAbstract:Photon number resolving detectors can enhance the performance of many practical quantum cryptographic setups. In this paper, we employ a simple method to estimate the statistics provided by such a photon number resolving detector using only a threshold detector together with a variable attenuator. This idea is similar in spirit to that of the decoy state technique, and is especially suited to those scenarios where only a few parameters of the photon number statistics of the incoming signals have to be estimated. As an illustration of the potential applicability of the method in quantum communication protocols, we use it to prove security of an entanglement-based quantum Key Distribution scheme with an untrusted source without the need for a squash model and by solely using this extra idea. In this sense, this detector decoy method can be seen as a different conceptual approach to adapt a single-photon security proof to its physical, full optical implementation. We show that in this scenario, the legitimate users can now even discard the double click events from the raw Key data without compromising the security of the scheme, and we present simulations on the performance of the BB84 and the 6-state quantum Key Distribution protocols.
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detector decoy quantum Key Distribution
arXiv: Quantum Physics, 2008Co-Authors: Marcos Curty, Norbert Lutkenhaus, Tobias MoroderAbstract:Photon number resolving detectors can enhance the performance of many practical quantum cryptographic setups. In this paper, we employ a simple method to estimate the statistics provided by such a photon number resolving detector using only a threshold detector together with a variable attenuator. This idea is similar in spirit to that of the decoy state technique, and is specially suited for those scenarios where only a few parameters of the photon number statistics of the incoming signals have to be estimated. As an illustration of the potential applicability of the method in quantum communication protocols, we use it to prove security of an entanglement based quantum Key Distribution scheme with an untrusted source without the need of a squash model and by solely using this extra idea. In this sense, this detector decoy method can be seen as a different conceptual approach to adapt a single photon security proof to its physical, full optical implementation. We show that in this scenario the legitimate users can now even discard the double click events from the raw Key data without compromising the security of the scheme, and we present simulations on the performance of the BB84 and the 6-state quantum Key Distribution protocols.
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entanglement as a precondition for secure quantum Key Distribution
Physical Review Letters, 2004Co-Authors: Marcos Curty, Maciej Lewenstein, Norbert LutkenhausAbstract:We demonstrate that a necessary precondition for an unconditionally secure quantum Key Distribution is that both sender and receiver can use the available measurement results to prove the presence of entanglement in a quantum state that is effectively distributed between them. One can thus systematically search for entanglement using the class of entanglement witness operators that can be constructed from the observed data. We apply such analysis to two well-known quantum Key Distribution protocols, namely, the 4-state protocol and the 6-state protocol. As a special case, we show that, for some asymmetric error patterns, the presence of entanglement can be proven even for error rates above 25% (4-state protocol) and 33% (6-state protocol).
Romain Alleaume - One of the best experts on this subject based on the ideXlab platform.
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Worldwide standardization activity for quantum Key Distribution
2014 IEEE Globecom Workshops (GC Wkshps), 2014Co-Authors: Romain Alleaume, Vincente Martin, Alan Mink, Ivo Pietro Degiovanni, Momtchil Peev, Marco Lucamarini, Christopher J. Chunnilall, Martin WardAbstract:We discuss the on-going worldwide activity to develop forward looking standards for quantum Key Distribution (QKD) in the European Telecommunications Standards Institute (ETSI) QKD industry specification group (ISG). The long term goal is to develop a certification methodology that bridges the gap between theoretical proofs and practical implementations with imperfect devices. Current efforts are focused on the handling of side channels and characterization of the most relevant components.
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multidimensional reconciliation for a continuous variable quantum Key Distribution
Physical Review A, 2008Co-Authors: Anthony Leverrier, Joseph J. Boutros, Romain Alleaume, Gilles Zemor, Philippe GrangierAbstract:We propose a method for extracting an errorless secret Key in a continuous-variable quantum Key Distribution protocol, which is based on Gaussian modulation of coherent states and homodyne detection. The crucial feature is an eight-dimensional reconciliation method based on the algebraic properties of octonions. Since the protocol does not use any post-selection, it can be proven secure against arbitrary collective attacks by using well-established theorems on the optimality of Gaussian attacks. By using this coding scheme with an appropriate signal-to-noise ratio, the distance for a secure continuous-variable quantum Key Distribution can be significantly extended.
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Multidimensional reconciliation for continuous-variable quantum Key Distribution
Physical Review A, 2008Co-Authors: Anthony Leverrier, Romain Alleaume, Gilles Zemor, Joseph Boutros, Philippe GrangierAbstract:We propose a new method for extracting an errorless secret Key in a continuous-variable quantum Key Distribution protocol, which is based on Gaussian modulation of coherent states and homodyne detection. The crucial novel feature is an eight-dimensional reconciliation method, based on the algebraic properties of octonions. Since the protocol does not use any postselection, it can be proven secure against arbitrary collective attacks, by using well-established theorems on the optimality of Gaussian attacks. By using this new coding scheme with an appropriate signal to noise ratio, the distance for secure continuous-variable quantum Key Distribution can be significantly extended.
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SECOQC White Paper on Quantum Key Distribution and Cryptography
arXiv preprint quant-ph 0701168, 2007Co-Authors: Romain Alleaume, Mark Godfrey, Thierry Debuisschert, Cyril Branciard, Jan Bouda, Nicolas Gisin, Thomas Langer, Philippe Grangier, Mehrdad Dianati, Anthony LeverrierAbstract:The SECOQC White Paper on Quantum Key Distribution and Cryptography is the outcome on a thorough consultation and discussion among the participants of the European project SECOQC (www.secoqc.net). This paper is a review article that attempts to position Quantum Key Distribution (QKD) in terms of cryptographic applications. A detailed comparison of QKD with the solutions currently in use to solve the Key Distribution problem, based on classical cryptography, is provided. We also detail how the work on QKD networks lead within SECOQC will allow the deployment of long-distance secure communication infrastructures based on quantum cryptography. The purpose of the White Paper is finally to promote closer collaboration between classical and quantum cryptographers. We believe that very fruitful research, involving both communities, could emerge in the future years and try to sketch what may be the next challenges in this direction.
Marcos Curty - One of the best experts on this subject based on the ideXlab platform.
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insecurity of detector device independent quantum Key Distribution
Physical Review Letters, 2016Co-Authors: Shihan Sajeed, Anqi Huang, Shihai Sun, Vadim Makarov, Marcos CurtyAbstract:Detector-device-independent quantum Key Distribution (DDI-QKD) held the promise of being robust to detector side channels, a major security loophole in quantum Key Distribution (QKD) implementations. In contrast to what has been claimed, however, we demonstrate that the security of DDI-QKD is not based on postselected entanglement, and we introduce various eavesdropping strategies that show that DDI-QKD is in fact insecure against detector side-channel attacks as well as against other attacks that exploit devices' imperfections of the receiver. Our attacks are valid even when the QKD apparatuses are built by the legitimate users of the system themselves, and thus, free of malicious modifications, which is a Key assumption in DDI-QKD.
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detector decoy quantum Key Distribution
New Journal of Physics, 2009Co-Authors: Marcos Curty, Norbert Lutkenhaus, Tobias MoroderAbstract:Photon number resolving detectors can enhance the performance of many practical quantum cryptographic setups. In this paper, we employ a simple method to estimate the statistics provided by such a photon number resolving detector using only a threshold detector together with a variable attenuator. This idea is similar in spirit to that of the decoy state technique, and is especially suited to those scenarios where only a few parameters of the photon number statistics of the incoming signals have to be estimated. As an illustration of the potential applicability of the method in quantum communication protocols, we use it to prove security of an entanglement-based quantum Key Distribution scheme with an untrusted source without the need for a squash model and by solely using this extra idea. In this sense, this detector decoy method can be seen as a different conceptual approach to adapt a single-photon security proof to its physical, full optical implementation. We show that in this scenario, the legitimate users can now even discard the double click events from the raw Key data without compromising the security of the scheme, and we present simulations on the performance of the BB84 and the 6-state quantum Key Distribution protocols.
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detector decoy quantum Key Distribution
arXiv: Quantum Physics, 2008Co-Authors: Marcos Curty, Norbert Lutkenhaus, Tobias MoroderAbstract:Photon number resolving detectors can enhance the performance of many practical quantum cryptographic setups. In this paper, we employ a simple method to estimate the statistics provided by such a photon number resolving detector using only a threshold detector together with a variable attenuator. This idea is similar in spirit to that of the decoy state technique, and is specially suited for those scenarios where only a few parameters of the photon number statistics of the incoming signals have to be estimated. As an illustration of the potential applicability of the method in quantum communication protocols, we use it to prove security of an entanglement based quantum Key Distribution scheme with an untrusted source without the need of a squash model and by solely using this extra idea. In this sense, this detector decoy method can be seen as a different conceptual approach to adapt a single photon security proof to its physical, full optical implementation. We show that in this scenario the legitimate users can now even discard the double click events from the raw Key data without compromising the security of the scheme, and we present simulations on the performance of the BB84 and the 6-state quantum Key Distribution protocols.
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entanglement as a precondition for secure quantum Key Distribution
Physical Review Letters, 2004Co-Authors: Marcos Curty, Maciej Lewenstein, Norbert LutkenhausAbstract:We demonstrate that a necessary precondition for an unconditionally secure quantum Key Distribution is that both sender and receiver can use the available measurement results to prove the presence of entanglement in a quantum state that is effectively distributed between them. One can thus systematically search for entanglement using the class of entanglement witness operators that can be constructed from the observed data. We apply such analysis to two well-known quantum Key Distribution protocols, namely, the 4-state protocol and the 6-state protocol. As a special case, we show that, for some asymmetric error patterns, the presence of entanglement can be proven even for error rates above 25% (4-state protocol) and 33% (6-state protocol).
