Search

Your search keyword '"Van Assche G"' showing total 1,193 results
Start Over Author "Van Assche G"
1,193 results on '"Van Assche G"'

5. Secure Coherent-state Quantum Key Distribution Protocols with Efficient Reconciliation

Author

Van Assche, G., Iblisdir, S., and Cerf, N. J.

Subjects
Quantum Physics
Abstract

We study the equivalence between a realistic quantum key distribution protocol using coherent states and homodyne detection and a formal entanglement purification protocol. Maximally-entangled qubit pairs that one can extract in the formal protocol correspond to secret key bits in the realistic protocol. More specifically, we define a qubit encoding scheme that allows the formal protocol to produce more than one entangled qubit pair per coherent state, or equivalently for the realistic protocol, more than one secret key bit. The entanglement parameters are estimated using quantum tomography. We analyze the properties of the encoding scheme and investigate its application to the important case of the attenuation channel., Comment: REVTeX, 11 pages, 2 figures

Published
2004
Full Text
View/download PDF

6. Security of Quantum Key Distribution with Coherent States and Homodyne Detection

Author

Iblisdir, S., Van Assche, G., and Cerf, N. J.

Subjects
Quantum Physics
Abstract

We assess the security of a quantum key distribution protocol relying on the transmission of Gaussian-modulated coherent states and homodyne detection. This protocol is shown to be equivalent to a squeezed state protocol based on a CSS code construction, and is thus provably secure against any eavesdropping strategy. We also briefly show how this protocol can be generalized in order to improve the net key rate., Comment: 7 pages

Published
2003
Full Text
View/download PDF

7. Quantum key distribution using gaussian-modulated coherent states

Author

Grosshans, F., Van Assche, G., Wenger, J., Brouri, R., Cerf, N. J., and Grangier, Ph.

Subjects
Quantum Physics
Abstract

Quantum continuous variables are being explored as an alternative means to implement quantum key distribution, which is usually based on single photon counting. The former approach is potentially advantageous because it should enable higher key distribution rates. Here we propose and experimentally demonstrate a quantum key distribution protocol based on the transmission of gaussian-modulated coherent states (consisting of laser pulses containing a few hundred photons) and shot-noise-limited homodyne detection; squeezed or entangled beams are not required. Complete secret key extraction is achieved using a reverse reconciliation technique followed by privacy amplification. The reverse reconciliation technique is in principle secure for any value of the line transmission, against gaussian individual attacks based on entanglement and quantum memories. Our table-top experiment yields a net key transmission rate of about 1.7 megabits per second for a loss-free line, and 75 kilobits per second for a line with losses of 3.1 dB. We anticipate that the scheme should remain effective for lines with higher losses, particularly because the present limitations are essentially technical, so that significant margin for improvement is available on both the hardware and software., Comment: 8 pages, 4 figures

Published
2003
Full Text
View/download PDF

8. Reconciliation of a Quantum-Distributed Gaussian Key

Author

Van Assche, G., Cardinal, J., and Cerf, N. J.

Subjects
Computer Science - Cryptography and Security, Quantum Physics, E.3
Abstract

Two parties, Alice and Bob, wish to distill a binary secret key out of a list of correlated variables that they share after running a quantum key distribution protocol based on continuous-spectrum quantum carriers. We present a novel construction that allows the legitimate parties to get equal bit strings out of correlated variables by using a classical channel, with as few leaked information as possible. This opens the way to securely correcting non-binary key elements. In particular, the construction is refined to the case of Gaussian variables as it applies directly to recent continuous-variable protocols for quantum key distribution., Comment: 8 pages, 4 figures. Submitted to the IEEE for possible publication. Revised version to improve its clarity

Published
2001
Full Text
View/download PDF

9. Cloning and Cryptography with Quantum Continuous Variables

Author

Cerf, N. J., Iblisdir, S., and Van Assche, G.

Subjects
Quantum Physics
Abstract

The cloning of quantum variables with continuous spectra is investigated. We define a Gaussian 1-to-2 cloning machine, which copies equally well two conjugate variables such as position and momentum or the two quadrature components of a light mode. The resulting cloning fidelity for coherent states, namely $F=2/3$, is shown to be optimal. An asymmetric version of this Gaussian cloner is then used to assess the security of a continuous-variable quantum key distribution scheme that allows two remote parties to share a Gaussian key. The information versus disturbance tradeoff underlying this continuous quantum cryptographic scheme is then analyzed for the optimal individual attack. Methods to convert the resulting Gaussian keys into secret key bits are also studied. The extension of the Gaussian cloner to optimal $N$-to-$M$ continuous cloners is then discussed, and it is shown how to implement these cloners for light modes, using a phase-insensitive optical amplifier and beam splitters. Finally, a phase-conjugated inputs $(N,N')$-to-$(M,M')$ continuous cloner is defined, yielding $M$ clones and $M'$ anticlones from $N$ replicas of a coherent state and $N'$ replicas of its phase-conjugate (with $M'-M=N'-N$). This novel kind of cloners is shown to outperform the standard $N$-to-$M$ cloners in some situations., Comment: 8 pages, 3 figures, submitted to the special issue of the European Physical Journal D on "Quantum interference and cryptographic keys: novel physics and advancing technologies", proceedings of the conference QUICK 2001, Corsica, April 7-13 2001. Minor correction, references added

Published
2001
Full Text
View/download PDF

10. Quantum Distribution of Gaussian Keys with Squeezed States

Author

Cerf, N. J., Levy, M., and Van Assche, G.

Subjects
Quantum Physics
Abstract

A continuous key distribution scheme is proposed that relies on a pair of canonically conjugate quantum variables. It allows two remote parties to share a secret Gaussian key by encoding it into one of the two quadrature components of a single-mode electromagnetic field. The resulting quantum cryptographic information vs disturbance tradeoff is investigated for an individual attack based on the optimal continuous cloning machine. It is shown that the information gained by the eavesdropper then simply equals the information lost by the receiver., Comment: 5 pages, RevTex

Published
2000
Full Text
View/download PDF

13. FEM modelling to predict spatiotemporally resolved water uptake in organic coatings: Experimental validation by odd random phase electrochemical impedance spectroscopy measurements

Author

Meeusen, M. (author), van Dam, J.P.B. (author), Madelat, N. (author), Jalilian, E. (author), Wouters, B. (author), Hauffman, T. (author), Van Assche, G. (author), Mol, J.M.C. (author), Hubin, A. (author), Terryn, H.A. (author), Meeusen, M. (author), van Dam, J.P.B. (author), Madelat, N. (author), Jalilian, E. (author), Wouters, B. (author), Hauffman, T. (author), Van Assche, G. (author), Mol, J.M.C. (author), Hubin, A. (author), and Terryn, H.A. (author)

Abstract

In this work, a new finite element modelling (FEM) approach is followed to model spatiotemporally resolved water uptake in organic coatings. To this aim, we start from a physical model, where not only Fickian diffusion of water is taken into account but also the adsorption/desorption reaction of water on the polymer matrix. Starting from a number of important coating properties and crucial model parameters, derived from gravimetric and Fourier transform infrared (FTIR) measurements as the model input, the local water concentration over the coating thickness as a function of time is modelled for a polyethylene glycol diacrylate (PEGDA) coating. The modelled water concentration is then used to calculate virtual capacitance values which are evaluated against experimental capacitance values extracted from impedance measurements. The constraints of the FEM model and ORP-EIS experiments and the discrepancies between them are critically discussed in order to carry out a meaningful model validation, eventually leading to model improvements., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Team Yaiza Gonzalez Garcia, Team Arjan Mol

Published
2023
Full Text
View/download PDF

19. Incidence and Predictors of Success of Adalimumab Dose Escalation and De-escalation in Ulcerative Colitis: a Real-World Belgian Cohort Study

Author

Van de Vondel, Saartje, Baert, Filip, Reenaers, Christine, Vanden Branden, Stijn, Amininejad, Leila, Dewint, Pieter, Van Moerkercke, Wouter, Rahier, Jean-François, Hindryckx, Pieter, Bossuyt, Peter, Ferrante, Marc, Baert, F, De Wulf, D, Moortgat, L, De Cock, E, Decaestecker, L, D’Hondt, A, Van Moerkercke, W, Himpe, S, Dewint, P, Reenaers, C, Van Kemzeke, C, Louis, E, Rahier, J F, Amininejad, L, Franchimont, D, Wambacq, V, Bossuyt, P, Van de Schoot, I, Asnong, K, Vanden Branden, S, Sterckx, A, Hindryckx, P, De Vos, M, Ferrante, M, Noman, M, Vermeire, S, Van Assche, G, Franchimont, D, Rahier, J -F, Ferrante, M, and Vermeire, S

Published
2018
Full Text
View/download PDF

20. Long-term outcome of patients with steroid-refractory acute severe UC treated with ciclosporin or infliximab

Author

Laharie, D, Bourreille, A, Branche, J, Allez, M, Bouhnik, Y, Filippi, J, Zerbib, F, Savoye, G, Vuitton, L, Moreau, J, Amiot, A, Cosnes, J, Ricart, E, Dewit, O, Lopez-Sanroman, A, Fumery, M, Carbonnel, F, Bommelaer, G, Coffin, B, Roblin, X, van Assche, G, Esteve, M, Farkkila, M, Gisbert, JP, Marteau, P, Nahon, S, de Vos, M, Lambert, J, Mary, JY, and Louis, E

Published
2018
Full Text
View/download PDF

30. Imaging techniques for assessment of inflammatory bowel disease: Joint ECCO and ESGAR evidence-based consensus guidelines

Author

Panes, J., Bouhnik, Y., Reinisch, W., Stoker, J., Taylor, S.A., Baumgart, D.C., Danese, S., Halligan, S., Marincek, B., Matos, C., Peyrin-Biroulet, L., Rimola, J., Rogler, G., van Assche, G., Ardizzone, S., Ba-Ssalamah, A., Bali, M.A., Bellini, D., Biancone, L., Castiglione, F., Ehehalt, R., Grassi, R., Kucharzik, T., Maccioni, F., Maconi, G., Magro, F., Martín-Comín, J., Morana, G., Pendsé, D., Sebastian, S., Signore, A., Tolan, D., Tielbeek, J.A., Weishaupt, D., Wiarda, B., and Laghi, A.

Published
2013
Full Text
View/download PDF

36. P522 A multicenter study to validate Magnetic Resonance Enterography against histological assessments of stenotic disease in patients with Crohnʼs disease

Author

Coimbra, A., Rimola, J., Cuatrecasas, M., De Hertogh, G., Van Assche, G., Vanslembrouck, R., Glerup, H., Hedemann Nielsen, A., Hagemann-Madsen, R., Bouhnik, Y., Zappa, M., Cazals-Hatem, D., DʼHaens, G., Stoker, J., Meijer, S., Rogler, G., Boss, A., Weber, A., Zhao, R., Keir, M., Scherl, A., deCrespigny, A., Lu, T., and Panes, J.

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results