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See detailCryptanalysis, Reverse-Engineering and Design of Symmetric Cryptographic Algorithms
Perrin, Léo Paul UL

Doctoral thesis (2017)

In this thesis, I present the research I did with my co-authors on several aspects of symmetric cryptography from May 2013 to December 2016, that is, when I was a PhD student at the university of ... [more ▼]

In this thesis, I present the research I did with my co-authors on several aspects of symmetric cryptography from May 2013 to December 2016, that is, when I was a PhD student at the university of Luxembourg under the supervision of Alex Biryukov. My research has spanned three different areas of symmetric cryptography. In Part I of this thesis, I present my work on lightweight cryptography. This field of study investigates the cryptographic algorithms that are suitable for very constrained devices with little computing power such as RFID tags and small embedded processors such as those used in sensor networks. Many such algorithms have been proposed recently, as evidenced by the survey I co-authored on this topic. I present this survey along with attacks against three of those algorithms, namely GLUON, PRINCE and TWINE. I also introduce a new lightweight block cipher called SPARX which was designed using a new method to justify its security: the Long Trail Strategy. Part II is devoted to S-Box reverse-engineering, a field of study investigating the methods recovering the hidden structure or the design criteria used to build an S-Box. I co-invented several such methods: a statistical analysis of the differential and linear properties which was applied successfully to the S-Box of the NSA block cipher Skipjack, a structural attack against Feistel networks called the yoyo game and the TU-decomposition. This last technique allowed us to decompose the S-Box of the last Russian standard block cipher and hash function as well as the only known solution to the APN problem, a long-standing open question in mathematics. Finally, Part III presents a unifying view of several fields of symmetric cryptography by interpreting them as purposefully hard. Indeed, several cryptographic algorithms are designed so as to maximize the code size, RAM consumption or time taken by their implementations. By providing a unique framework describing all such design goals, we could design modes of operations for building any symmetric primitive with any form of hardness by combining secure cryptographic building blocks with simple functions with the desired form of hardness called plugs. Alex Biryukov and I also showed that it is possible to build plugs with an asymmetric hardness whereby the knowledge of a secret key allows the privileged user to bypass the hardness of the primitive. [less ▲]

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See detailLe travail frontalier au Luxembourg . Développement, enjeux et perspectives
Pigeron-Piroth, Isabelle UL; Belkacem, Rachid; Clément, Franz

Conference given outside the academic context (2017)

Le travail frontalier au Luxembourg a connu un fort développement ces trois dernières décennies, avec une multiplication des effectifs par dix. En janvier 2017, environ 180 000 salariés frontaliers ... [more ▼]

Le travail frontalier au Luxembourg a connu un fort développement ces trois dernières décennies, avec une multiplication des effectifs par dix. En janvier 2017, environ 180 000 salariés frontaliers travaillent au Grand- Duché de Luxembourg (IGSS). Ces femmes et ces hommes constituent un important facteur de développement économique et social pour les territoires de la Grande Région. Cette conférence vise à répondre à des questions essentielles : • Quelles sont les caractéristiques socioéconomiques du travail frontalier ? • Qui sont ces travailleurs mobiles qui vivent l’Europe au quotidien ? • Quelle est leur implication dans la vie économique et sociale locale (dans la région de travail comme celle de résidence) ? • Quelles sont les conséquences de la forte hausse de leur nombre pour les territoires frontaliers du Luxembourg ? [less ▲]

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See detailA New Global Vertical Land Movement Data Set from the TIGA Combined
Hunegnaw, Addisu UL; Teferle, Felix Norman UL; Abraha, Kibrom Ebuy UL

Poster (2017, April 23)

Globally averaged sea level has been estimated from the network of tide gauges installed around the world since the 19th century. These mean sea level (MSL) records provide sea level relative to a nearby ... [more ▼]

Globally averaged sea level has been estimated from the network of tide gauges installed around the world since the 19th century. These mean sea level (MSL) records provide sea level relative to a nearby tide gauge benchmark (TGBM), which allows for the continuation of the instrumental record in time. Any changes in the benchmark levels, induced by vertical land movements (VLM) affect the MSL records and hence sea level estimates. Over the last two decades sea level has also been observed using satellite altimeters. While the satellite observations are globally more homogeneous providing a picture of sea level not confined to coastlines, they require the VLM-corrected MSL records for the bias calibration of instrumental drifts. Without this calibration altimeter instruments from different missions cannot be combined. GPS has made it possible to obtain highly accurate estimates of VLM in a geocentric reference frame for stations at or close to tide gauges. Under the umbrella of the International GNSS Service (IGS), the Tide Gauge Benchmark Monitoring (TIGA) Working Group (WG) has been established to apply the expertise of the GNSS community to solving issues related to the accuracy and reliability of the vertical component to provide estimates of VLM in a well-defined global reference frame. To achieve this objective, five TIGA Analysis Centers (TACs) contributed re-processed global GPS network solutions to TIGA, employing the latest bias models and processing strategies in accordance with the second re-processing campaign (repro2) of the IGS. These solutions include those of the British Isles continuous GNSS Facility – University of Luxembourg consortium (BLT), the German Research Centre for Geosciences (GFZ) Potsdam, the German Geodetic Research Institute (DGF) at the Technical University of Munich, Geoscience Australia (AUT) and the University of La Rochelle (ULR). In this study we present to the sea level community an evaluation of the VLM estimates from the first combined solution from the IGS TIGA WG. The TAC solutions include more than 700 stations and span the common period 1995-2014. The combined solution was computed by the TIGA Combination Centre (TCC) at the University of Luxembourg, which used the Combination and Analysis of Terrestrial Reference Frame (CATREF) software package for this purpose. This first solution forms Release 1.0 and further releases will be made available after further reprocessing campaigns. We evaluate the combined solution internally using the TAC solutions and externally using solutions from the IGS and the ITRF2008. The derived VLM estimates have undergone an initial evaluation and should be considered as the primary TIGA product for the sea level community to correct MSL records for land level changes [less ▲]

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See detailMore or Less Intergovernmental Cooperation Within the New EMU?
Allemand, Frederic UL

in Daniele, Luigi; Simone, Pierluigi; Cisotta, Roberto (Eds.) Democracy in the EMU in the Aftermath of the Crisis (2017)

This chapter aims to analyse the recent shift in the allocation of powers within the EMU institutional framework. In the words of Angela Merkel, a new Union method is emerging from the Lisbon Treaty. The ... [more ▼]

This chapter aims to analyse the recent shift in the allocation of powers within the EMU institutional framework. In the words of Angela Merkel, a new Union method is emerging from the Lisbon Treaty. The management of the subprime crisis and sovereign debt crisis gave rise to practical institutional arrangements and the adoption of new secondary law whereby the European Council, as well as the Euro Summit were conferred on new political responsibilities. However, as we argue, this development in intergovernmental cooperation takes place with proper regard for the institutional balance and the complex system for the balancing of powers within the EMU. Following all the crises and reforms, EMU governance is neither more supranational nor more intergovernmental. It is both at once. To our way of thinking, to try to set the two approaches against each other would be a sterile exercise. EMU governance—and, in a broader sense, EU governance—is intergovernmental and supranational. It cannot be otherwise, so long as the EU bears the imprint of a twofold requirement: to achieve unity while respecting diversity. [less ▲]

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See detailWeinhandel und Weinkonsum in der Stadt Luxemburg im 15. Jahrhundert
Pauly, Michel UL

Conference given outside the academic context (2017)

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See detailDynamic qualitative filtering for linked (geo)visualisations: a prototype for exploring the collective memory of Instagram posts
Jones, Catherine UL; Guido, Daniele UL; Severo, Marta

Scientific Conference (2017, April 20)

This paper describes a prototype geo extension to an open source graph-based tool designed for analysing co-occurrence in large multimedia collections of historical resources. Employing an ... [more ▼]

This paper describes a prototype geo extension to an open source graph-based tool designed for analysing co-occurrence in large multimedia collections of historical resources. Employing an interdisciplinary approach, combining tools and practices from humanities and geography, we explore how it can be extended to facilitate both social and spatial enquiry. For the prototype development we use Instagram resources that reference the Via Francigena – a significant cultural route connecting Canterbury, UK and Rome, Italy. The resulting tool facilitates dynamic qualitative filtering and multilevel views to explore the social-spatial collective memory of this cultural route [less ▲]

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See detailNew Luxembourg Nationality Law came into force on 1 April
Scuto, Denis UL

Report (2017)

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See detailSur les représentations galoisiennes des formes modulaires de Hilbert de poids un en caractéristique p
Wiese, Gabor UL

Presentation (2017, April 11)

Dans cet exposé, je vais donner les idées principales de mon travail avec Mladen Dimitrov dans lequel nous démontrons que la représentation galoisienne associée à toute forme modulaire de Hilbert de poids ... [more ▼]

Dans cet exposé, je vais donner les idées principales de mon travail avec Mladen Dimitrov dans lequel nous démontrons que la représentation galoisienne associée à toute forme modulaire de Hilbert de poids un en caractéristique p et de niveau premier à p est non-ramifiée en p. Ce résultat s'applique notamment à des formes qui ne se relèvent pas en caractéristique zéro, et peut être vu comme la précision d'un aspect du poids dans la généralisation de la conjecture de modularité de Serre aux formes de Hilbert. [less ▲]

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See detailEconomic Downturns, Retirement and Long-Term Cognitive Function Among Older Americans
Hessel, Philipp; Riumallo-Herl, Carlos; Leist, Anja UL et al

in Journals of Gerontology Series B : Psychological Sciences & Social Sciences (2017)

Objective: Workers approaching retirement may be particularly vulnerable to economic downturns. This study assesses whether exposure to economic downturns around retirement age leads to poorer cognitive ... [more ▼]

Objective: Workers approaching retirement may be particularly vulnerable to economic downturns. This study assesses whether exposure to economic downturns around retirement age leads to poorer cognitive function in later life. Method: Longitudinal data for 13,577 individuals in the Health and Retirement Study were linked to unemployment rates in state of residence. Random- and fixed-effect models were used to examine whether downturns at 55–64 years of age were associated with cognitive functioning levels and decline at ≥65 years, measured by the Wechsler Adult Intelligence Scale-Revised. Results: Longer exposure to downturns at 55–64 years of age was associated with lower levels of cognitive function at ≥65 years. Compared to individuals experiencing only up to 1 year in a downturn at 55–64 years of age, individuals experiencing two downturns at these ages had 0.09 point (95% Confidence Interval [CI, −0.17, −0.02]) lower cognitive functioning scores at ≥65 years (3 years: b = −0.17, 95%CI [−0.29, −0.06]; 4 years: b = −0.14, 95%CI [−0.25, −0.02]; ≥5 years: b = −0.22, 95%CI [−0.38, −0.06]). Downturns at 55–64 years of age were not associated with rates of cognitive decline. Discussion: Exposure to downturns around retirement is associated with a long-lasting decline in cognitive function in later life. Policies mitigating the impact of downturns on older workers may help to maintain cognitive function in later life. [less ▲]

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See detailNos jardins sont de terre rouge
Scuto, Denis UL

Article for general public (2017)

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See detailProceedings of the 2nd International Workshop on Exploring Old Maps
van Dijk, Thomas; Schommer, Christoph UL

Book published by University of Würzburg - 2nd (2017)

Many libraries own an extensive collection of historical maps. Beside their value as historical objects, these maps are an important source of information for researchers in various scientific disciplines ... [more ▼]

Many libraries own an extensive collection of historical maps. Beside their value as historical objects, these maps are an important source of information for researchers in various scientific disciplines. This ranges from the actual history of cartography and general history to the geographic and social sciences. With the progressing digitisation of libraries and archives, these maps become more easily available to a larger public. A basic level of digitisation consists of scanned bitmap images, tagged with some basic bibliographic information such as title, author and year of production. In order to make the maps more accessible, further metadata describing the contained information is desirable. This would enable more user-friendly interfaces, relevant queries of a database, and automatic analyses. This international workshop provides a forum for the communication of results that may be useful to the community. Researchers and practitioners of many areas working on unlocking the content of old maps have contributed to this year’s program — humanities scholars, developers, computer and information scientists and map enthusiasts. [less ▲]

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See detailFindel: Secure Derivative Contracts for Ethereum
Biryukov, Alex UL; Khovratovich, Dmitry UL; Tikhomirov, Sergei UL

Scientific Conference (2017, April 07)

Blockchain-based smart contracts are considered a promising technology for handling financial agreements securely. In order to realize this vision, we need a formal language to unambiguously describe ... [more ▼]

Blockchain-based smart contracts are considered a promising technology for handling financial agreements securely. In order to realize this vision, we need a formal language to unambiguously describe contract clauses. We introduce Findel -- a purely declarative financial domain-specific language (DSL) well suited for implementation in blockchain networks. We implement an Ethereum smart contract that acts as a marketplace for Findel contracts and measure the cost of its operation. We analyze challenges in modeling financial agreements in decentralized networks and outline directions for future work. [less ▲]

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See detailStatistical Comparison and Combination of GPS, GLONASS, and Multi-GNSS Multipath Reflectometry Applied to Snow Depth Retrieval
Tabibi, Sajad UL; Geremia-Nievinski, Felipe; van Dam, Tonie UL

in IEEE Transactions on Geoscience and Remote Sensing (2017), (99),

Global navigation satellite system (GNSS) multipath reflectometry (MR) has emerged as a new technique that uses signals of opportunity broadcast by GNSS satellites and tracked by ground-based receivers to ... [more ▼]

Global navigation satellite system (GNSS) multipath reflectometry (MR) has emerged as a new technique that uses signals of opportunity broadcast by GNSS satellites and tracked by ground-based receivers to retrieve environmental variables such as snow depth. The technique is based on the simultaneous reception of direct or line-of-sight (LOS) transmissions and corresponding coherent surface reflections (non-LOS). Until recently, snow depth retrieval algorithms only used legacy and modernized GPS signals. Using multiple GNSS constellations for reflectometry would improve GNSS-MR applications by providing more observations from more satellites and independent signals (carrier frequencies and code modulations). We assess GPS and GLONASS for combined multi-GNSS-MR using simulations as well as field measurements. Synthetic observations for different signals indicated a lack of detectable interfrequency and intercode biases in GNSS-MR snow depth retrievals. Received signals from a GNSS station continuously operating in France for a two-winter period are used for experimental snow depth retrieval. We perform an internal validation of various GNSS signals against the proven GPS-L2-C signal, which was validated externally against in situ snow depth in previous studies. GLONASS observations required a more complex handling to account for topography because of its particular ground track repeatability. Signal intercomparison show an average correlation of 0.922 between different GPS snow depths and GPS-L2-CL, while GLONASS snow depth retrievals have an average correlation that exceeds 0.981. In terms of precision and accuracy, legacy GPS signals are worse, while GLONASS signals and modernized GPS signals are of comparable quality. Finally, we show how an optimal multi-GNSS combined daily snow depth time series can be formed employing variance factors with a ~59%-90% precision improvement compared to individual signal snow depth retrievals, resulting in snow depth retrieval with uncertainty of 1.3 cm. The developed combination strategy can also be applied for the European Galileo and the Chines BeiDou navigation systems. [less ▲]

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See detailAddressing climate change through green building in Luxembourg and Freiburg: achieving urban sustainability or business as usual?
JUNG ép. PRELLER, Bérénice UL

Scientific Conference (2017, April 07)

Grounded into critical literature on the green economy and ecological modernisation (e.g. Gibbs and Krueger 2007; Bina 2013; Whitehead 2013; Bailey and Caprotti 2014) the proposed contribution looks at ... [more ▼]

Grounded into critical literature on the green economy and ecological modernisation (e.g. Gibbs and Krueger 2007; Bina 2013; Whitehead 2013; Bailey and Caprotti 2014) the proposed contribution looks at climate policies focusing on green building in two city regions: Luxembourg (LU) and Freiburg (DE). Although they have engaged differently and at different points in time with the topic, both identify the built environment as key in reaching urban sustainability. Through the discursive analysis of policy and media documents, further contextualised with interviews of key local actors, I will inquire how far these green building policies, following their claim to be innovative and transformative, can indeed be considered to be so, further from their technological carbon-controlling dimension. I will focus specifically on the visions, rationales and justifications mobilised to show that, despite their apparently different conceptions, green building policies in both places are framed along a "sustainability (policy) fix" (While et al. 2004; Lombardi et al. 2011) prodded by the dominant socioeconomic consensus. In Luxembourg, green building is strongly articulated as a mean to pursuit the existing model of social affluence, while in Freiburg the citizen-led achievements of the 90's have been recuperated by the city administration to competitively position itself as a leader in green wealth and quality of living (Cidell 2012; Mössner 2016). I will conclude by illustrating how this materialises into concrete building projects with very similar (technological) focuses towards carbon controlling. [less ▲]

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See detail"Wie Zeki zu Göhtisch kommt": Lehrerkonstruktion im Dialog
Arend, Béatrice UL; Sunnen, Patrick UL

Scientific Conference (2017, April 07)

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See detailUsing Selene to Verify your Vote in JCJ
Iovino, Vincenzo UL; Rial Duran, Alfredo UL; Roenne, Peter UL et al

in Workshop on Advances in Secure Electronic Voting (VOTING'17) (2017, April 07)

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See detailExpanding the Interactome of TES by Exploiting TES Modules with Different Subcellular Localizations
SALA, Stefano; Van troys, Marleen; Medves, Sandrine et al

in Journal of Proteome Research (2017), doi: 10.1021/acs.jproteome.7b00034

Detailed reference viewed: 8 (0 UL)