Tradeoff Cryptanalysis of Memory-Hard Functions

in 21st International Conference on the Theory and Application of Cryptology and Information Security (2015, December)

We explore time-memory and other tradeoffs for memory-hard functions, which are supposed to impose significant computational and time penalties if less memory is used than intended. We analyze two schemes ... [more ▼]

We explore time-memory and other tradeoffs for memory-hard functions, which are supposed to impose significant computational and time penalties if less memory is used than intended. We analyze two schemes: Catena, which has been presented at Asiacrypt 2014, and Lyra2, the fastest finalist of the Password Hashing Competition (PHC). We demonstrate that Catena's proof of tradeoff resilience is flawed, and attack it with a novel \emph{precomputation tradeoff}. We show that using $M^{2/3}$ memory instead of $M$ we may have no time penalties. We further generalize our method for a wide class of schemes with predictable memory access. For Lyra2, which addresses memory unpredictability (depending on the input), we develop a novel \emph{ranking tradeoff} and show how to decrease the time-memory and the time-area product by significant factors. We also generalize the ranking method for a wide class of schemes with unpredictable memory access [less ▲]

Être adulte en sortant de structures d’Aide sociale à l’enfance, le capital social au cœur de la définition de l’autonomie

in Vie sociale (2015), Nouvelle série n°12

While the passage from youth to the age of adulthood is no longer generally signified at a specific age, for young people from child protection services this is not the case as it clearly corresponds to ... [more ▼]

While the passage from youth to the age of adulthood is no longer generally signified at a specific age, for young people from child protection services this is not the case as it clearly corresponds to the age of departure from the placement. Leaving the child protection structure is a crucial step. Professionals’ work involves preparing young people for leaving and thus “helping them towards autonomy”. This article deciphers factors that have an impact on this moment of time and can affect what happens later. It discusses the “injunction to be autonomous” and its’ consequences as signified at a relatively early age compared to other groups of young people. Young people from child protection do not have the benefit of a time period enabling them to live through life experiences and they are not permitted to be “young”. Furthermore, these young people and their families often have no social capital. This article shows how can professionals take theses aspects into account in their work with them. [less ▲]

A Markov chain dynamic model for trip generation and distribution based on CDR

in Periodica Polytechnica (2015)

Projet de recherche SDropSy, Université de Luxembourg QUE RESTE-T-IL À DIRE SUR LE DÉCROCHAGE SCOLAIRE ?

in Transfert (2015), 2015(Hiver), 8-9

Assessing the effect of unknown widespread perturbations in complex systems using the mu-gap

in EEE Conference on Decision and Control, Osaka, Japan, December 2015 (2015, December)

Avant-propos. Habiter l’espace post-yougoslave

in Revue d'Etudes Comparatives Est-Ouest (2015), 46(4), 7-34

Bestandsaufnahme zum Thema Verhütung und Sexualität: Auswertung der Umfrag "Gëff Gummi"

Report (2015)

Folk music: Luxembourg

in Leerssen, Joep (Ed.) Encyclopedia of Romantic Nationalism in Europe (2015)

FULL TEXT The first folksong collection in Luxembourg, Die luxemburger Volkslieder älterer Zeit, compiled by the folklorist and ethnologist Edmond de la Fontaine (alias Dicks, 1823-1891), was published ... [more ▼]

FULL TEXT The first folksong collection in Luxembourg, Die luxemburger Volkslieder älterer Zeit, compiled by the folklorist and ethnologist Edmond de la Fontaine (alias Dicks, 1823-1891), was published posthumously in 1904. It contains only forty songs, and due to the unscientific way they had been collected, some important information is missing; nonetheless it offers a first glipse into folksongs in 19th-century Luxembourg. Their lyrics were adapted to the Luxembourg context, although only a few songs originate from the country. A scholarly, methodical folksong collection following the model of Erk and Böhme’s Deutscher Liederhort (1893-94) was published in 1937, entitled Singendes Volk. Its author, Mattias Thill, a primary school teacher, spent about four decades collecting songs throughout the Grand Duchy; again, most songs are variants of existing songs of non-Luxembourgish origin, 65% from Germany and a mere 3% from France. The remaining 32% have Luxembourgish texts (which, again, speaks for their more complete integration into Luxembourg life, not necessarily for a Luxembourg origin). Indigenous songs are often related to the military history and to the fortress of Luxembourg. Folk music in Luxembourg is predominantly vocal, with the one curious exception of a mystical blind violin-playing minstrel, Matthias Schou (alias Blannen Theis, 1747-1824) who was led from parish fair to parish fair by his wife and entertained the peasant population with his songs. Until today no sources have been discovered, but it is assumed that this troubadour is at the origin of melodies gathered a century later. In three cases, songs were subsequently arranged to instrumental music at a later date and gained a persistent performative presence to the point of becoming markers of Luxembourgish musical identity: the Wilhelmus, the Song of the dancing Procession, and the Hämmelsmarsch The Wilhelmus is the anthem of the Grand-Ducal court (not of the country), and is performed at the occasion of an official appearance of the Grand-Duke or of a member of his family. The melody is a variant of the Dutch national anthem Wilhelmus van Nassouwe, evidently based on Mozart’s Seven variations on Wilem Van Nassau (1766, KV 25) The “Song of the Dancing Procession” originates from the famous Procession of Echternach, and is based on the German folksong Adam hatte sieben Söhn’, arranged to a Rheinländerpolka for wind band in a medium tempo suitable for pilgrims taking three steps forward and two steps backwards. The Hämmelsmarsch, a beggar song derived from a 14th-century shepherd’s fair song, was played by pipers and drummers while visitors had to pay a fee. Modern-day local wind bands maintain this tradition, strolling the streets during parish fairs and requesting financial donations while playing this song. [less ▲]

Designing for Embodied Interaction: Perceptual Motor Effects as Unintended Consequences

Presentation (2015, December)

When designing for embodied interactions, the convergence of spatial human behaviour with physical space is often not sufficiently considered. This can cause unintended consequences in the user experience ... [more ▼]

When designing for embodied interactions, the convergence of spatial human behaviour with physical space is often not sufficiently considered. This can cause unintended consequences in the user experience, whereby the user may or may not be aware of the effects. In this talk I will discuss a study that was conducted into the spatial player behaviour of a multiplayer game installation. The installation’s interface was designed for embodied interaction and required whole body movements to play the game. The spatial analysis investigated a range of players’ activities in the game-space which revealed synergistic effects combining perceptual-motor factors with game-strategy behaviour. As games are becoming increasingly embodied and social the study’s findings illustrate that the role of space should receive more attention which may also require for designers to incorporate new methodologies into the design process. [less ▲]

Identifying Biochemical Reaction Networks From Heterogeneous Datasets

in IEEE Conference on Decision and Control, Osaka, Japan, December 2015 (2015, December)