Cryptanalysis of Achterbahn

Abstract. We present several attacks against the Achterbahn stream cipher, which was proposed to the eSTREAM competition. We can break the reduced and the full version with complexity of 2 55 and 2 61 steps. Extensions of our attacks are also described to break modified versions of the Achterbahn stream cipher, which were proposed following the publication of preliminary cryptanalysis results. These attacks highlight some problems in the design principle of Achterbahn, i.e., combining the outputs of several nonlinear (but small) shift registers using a nonlinear (but rather sparse) output function.

Prepaid postage using pre-stamped envelopes to affect turnout costs

Voter participation in elections is important for representational reasons but also because it helps to support the legitimacy of the election outcome. In a recent paper, Schelker and Schneiter (2017) show with data from only one Swiss canton that a small policy intervention (return envelopes with prepaid postage) can lead to substantially increased voter turnout rates. We revisit this finding and extend the analysis to all cantons that allow municipalities to offer free return postage. We find that a credible estimate of the effect is somewhat smaller but still positive and significant. We also document that this effect is not constant but stronger for larger municipalities than for smaller municipalities. Our interviews point to a likely mechanism. These results show that return envelopes with prepaid postage are an effective policy to increase participation, but mostly for large municipalitie

Grundgeschichte und Chronik: Die Fragestellung der frühjüdischen Chronikbücher und ihre Haltung zur Mosesüberlieferung

The Chronicler used two types of sources in writing history: In general, the chronistic narration is based on the „Deuteronomistic history“ as it is called today. Nonetheless, the Pentateuch in its priestly components is another key to its concept. In his historical outline, the Chronicler is aware of differences of time: There is, first of all, the epoch of Moses and of the Mosaic institutions given to a wandering Israel. A new age, second, started with David gathering a scattered people toward the new center in Jerusalem. These epochs are characterized by both continuity in the worship of Yhwh and discontinuity of theperformance of that worship. The ark, the mobile sanctuary in the tent of the desert, was now to find its definite place and house, to be built and inhabited by Yhwh, prepared by David and finally realized by Solomon. According to the Chronicler, God’s word had been present in both epochs, but in different forms. Originally, it was given orally to Moses. Yet, the history of Israel as described by Chronicles refers to written documents (kakkātûb). In light of their attribution in Chronicles we should not call them „priestly“ – as it has been customary since the 19th century (de Wette, Wellhausen) –but more adequately „Mosaic“ tradition. For the Chronicler, such Mosaic tradition was applied and performed by David’s Israel. Of prime importance is the new position of Levi, Moses’ own tribe. According to the P-sources in the Pentateuch, the Levites had to do physical labour for the holy tent. But, in the era of the temple, they gained a new responsibility by interpreting, instructing and applying Tora in its broadest sense. The Priests's duties for their part are presupposed rather than itemized. Since the time of the Exodus – which is deliberately not a topic in Chronicles – they have remained the same. Decisive for the Chronicler is the new presence of Moses’ revelation in the ongoing history of Israel and its kings, accompanied and guided by Moses’ tribe, the Levites

Smart Cities and ICT – Insights from the Morgenstadt project

According to the United Nations, 60% of the world’s population will live in urban areas by 2030 (United Nations 2012). While many cities around the world are growing and expanding, at the same time, a big number of cities in the northern hemisphere is facing reverse trends, e.g. caused by the demographic change. As a result of these trends and the comprehensive globalization, cities are competing within a global market for companies and well educated inhabitants. As an additional challenge, the climate change revealed his powerful forces during the last decades as seen in hurricanes Katrina and Sandy in 2005 respectively 2012 or typhoon Haiyan in 2013. In this context, cities are facing an extremely difficult assignment: an innovative sustainable development of the city, including ecologic, economic and social dimensions. This task includes two central requirements, making the city livable on the one hand and resilient against external factors as natural disasters or other crises on the other. This paper outlines innovative approaches of cities all over the world, in order to achieve the goal of a sustainable city of tomorrow, concentrating on the contribution of innovative information and communication technologies (ICT). The paper is based on an interdisciplinary long-term research project called “Morgenstadt: City Insights” (m:ci), which analyzed innovative and sustainable solutions and projects of the city sectors mobility, water infrastructure, production and logistics, governance, buildings, energy, security and ICT in six leading cities around the world in order to identify common characteristics and structures of success stories. Therefore, the paper first presents the research methodology of the m:ci project, followed by an overview of the examined sectors, projects and cities. Subsequently the key findings regarding the ICT sector will be presented and the role of ICT for an innovative and sustainable city development will be outlined. In this context it will be elaborated for instance how ICT enables innovative solutions of other sectors and to which extent the collection and procession of urban data contributes to a sustainable development. Finally, the paper discusses the transferability of the identified approaches and tries to illustrate possible strategies to implement such innovative and sustainable solutions

A New Version of Grain-128 with Authentication

A new version of the stream cipher Grain-128 is proposed. The new version, Grain-128a, is strengthened against all known attacks and observations on the original Grain-128, and has built-in support for authentication. The changes are modest, keeping the basic structure of Grain-128. This gives a high confidence in Grain-128a and allows for easy updating of existing implementations

Application of relaxed eddy accumulation (REA) on managed grassland

Abstract. Relaxed eddy accumulation is applied for measuring fluxes of trace gases for which there is a lack of sensors fast enough in their resolution for eddy-covariance. On managed grasslands, the length of time between management events and the application of relaxed eddy accumulation has an essential influence on the determination of the proportionality factor b and thereby on the resulting flux. In this study this effect is discussed for the first time. Also, scalar similarity between proxy scalars and scalars of interest is affected until the ecosystem has completely recovered. Against this background, CO2 fluxes were continuously measured and 13CO2 isofluxes were determined with a high measurement precision on two representative days in summer 2010. This enabled the evaluation of the 13CO2 flux portion of the entire CO2 flux, in order to estimate potential influences on tracer experiments in ecosystem sciences and to compare a common method for the partitioning of the net ecosystem exchange into assimilation and respiration based on temperature and light response with an isotopic approach directly based on the isotope discrimination of the biosphere. </jats:p

La utilización de marfil de cachalote en el Calcolítico de Portugal

Scientific analysis were undertaken within a research project concerning ivory objects from the Chalcolithic to Early Bronze Age of the Iberian Peninsula. In several of the analyses of objects from Portuguese Estremadura, especially V-perforated buttons, we could detect for the first time the presence of sperm whale ivory. This highlights the advantage and necessity of scientific analysis of ivory. It also clearly demonstrates that not all ivory used was ivory from African or Asian elephants, but we also did find ivory from the extinct Elephas antiquus, the hippopotamus and in this case sperm-whale. Thus, already in the Chalcolithic the raw material provenience was highly diverse, which in the absence of scientific analysis might lead to an erroneous interpretation of prehistoric exchange networks. Different methods, including optical microscopy, measurement of hardness and specific gravity, Micro-Raman Spectroscopy, elemental analysis and Isotopic Ratio Mass Spectrometry have been applied. In this paper we present these methods and the results, and we discuss about the implications of these results for the reconstruction of prehistoric economy and life in this region. Finally, taking into account the natural conditions as well as prehistoric and historic data of whale hunting and scavenging of beached animals, we conclude that the most plausible explanation for the presence of sperm whale ivory in Chalcolithic Portugal is the use of the teeth obtained from stranded animals. This interpretation is possible because of the human populations using this ivory are those living close to the sea and exploiting – among others– marine resources.En el marco de un proyecto de investigación sobre objetos de marfil del Calcolítico al Bronce Antiguo en la Península Ibérica efectuamos análisis científicos. En varios de los objetos de la Estremadura portuguesa, en especial en los botones con perforación en V, detectamos por primera vez la presencia de marfil de cachalote. Así se demuestra claramente la ventaja y la necesidad de efectuar análisis científicos del marfil. No todo el marfil utilizado provenía de los elefantes africanos y asiáticos. Además encontramos marfil del desaparecido Elephas antiquus, de hipopótamo, y en este caso de cachalote. Así ya en el Calcolítico el origen de la materia prima era muy diverso, lo que en ausencia de análisis científicos puede conducir a una errónea interpretación de las redes prehistóricas de intercambio. Los métodos empleados fueron la microscopia óptica, la medición de la dureza y del peso específico, la espectroscopía Micro-Raman, el análisis elemental y la espectrometría isotópica de masas. En este trabajo presentamos estos métodos y los resultados. Además discutimos sus consecuencias para la reconstrucción de la economía y la vida de las sociedades prehistóricas de la región. Teniendo en cuenta las condiciones naturales y los datos prehistóricos e históricos sobre la caza de ballenas y el aprovechamiento de animales varados consideramos que la explicación más plausible de la presencia de marfil de cachalote en el caso del Calcolítico portugués es el uso de dientes de cachalotes varados. Cabe esta interpretación dado que las poblaciones que emplean este marfil son las que viven cerca del mar explotando, entre otros, los recursos marinos

Validation of Non-Restrictive Inertial Gait Analysis of Individuals with Incomplete Spinal Cord Injury in Clinical Settings

Inertial Measurement Units (IMUs) have gained popularity in gait analysis and human motion tracking, and they provide certain advantages over stationary line-of-sight-dependent Optical Motion Capture (OMC) systems. IMUs appear as an appropriate alternative solution to reduce dependency on bulky, room-based hardware and facilitate the analysis of walking patterns in clinical settings and daily life activities. However, most inertial gait analysis methods are unpractical in clinical settings due to the necessity of precise sensor placement, the need for well-performed calibration movements and poses, and due to distorted magnetometer data in indoor environments as well as nearby ferromagnetic material and electronic devices. To address these limitations, recent literature has proposed methods for self-calibrating magnetometer-free inertial motion tracking, and acceptable performance has been achieved in mechanical joints and in individuals without neurological disorders. However, the performance of such methods has not been validated in clinical settings for individuals with neurological disorders, specifically individuals with incomplete Spinal Cord Injury (iSCI). In the present study, we used recently proposed inertial motion-tracking methods, which avoid magnetometer data and leverage kinematic constraints for anatomical calibration. We used these methods to determine the range of motion of the Flexion/Extension (F/E) hip and Abduction/Adduction (A/A) angles, the F/E knee angles, and the Dorsi/Plantar (D/P) flexion ankle joint angles during walking. Data (IMU and OMC) of five individuals with no neurological disorders (control group) and five participants with iSCI walking for two minutes on a treadmill in a self-paced mode were analyzed. For validation purposes, the OMC system was considered as a reference. The mean absolute difference (MAD) between calculated range of motion of joint angles was 5.00°, 5.02°, 5.26°, and 3.72° for hip F/E, hip A/A, knee F/E, and ankle D/P flexion angles, respectively. In addition, relative stance, swing, double support phases, and cadence were calculated and validated. The MAD for the relative gait phases (stance, swing, and double support) was 1.7%, and the average cadence error was 0.09 steps/min. The MAD values for RoM and relative gait phases can be considered as clinically acceptable. Therefore, we conclude that the proposed methodology is promising, enabling non-restrictive inertial gait analysis in clinical settings