Ruhr-Universität Bochum (RUB): Open Journal Systems
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Leaky McEliece: Secret Key Recovery From Highly Erroneous Side-Channel Information
Get PDFThe McEliece cryptosystem is a strong contender for post-quantum schemes, including key encapsulation for confidentiality of key exchanges in network protocols. A McEliece secret key is a structured parity check matrix that is transformed via Gaussian elimination into an unstructured public key. We show that this transformation is highly critical with respect to side-channel leakage. We assume leakage of the elementary row operations during Gaussian elimination, motivated by McEliece implementations in the cryptographic libraries Classic McEliece and Botan.We propose a novel decoding algorithm to reconstruct a secret key from its public key with information from a Gaussian transformation leak. Even if the obtained side-channel leakage is extremely noisy, i.e., each bit is flipped with probability as high as r ≈ 0.4, we succeed to recover the secret key in a matter of minutes for all proposed (Classic) McEliece instantiations. Remarkably, for high-security McEliece parameters, our attack is more powerful in the sense that it can tolerate even larger r . We demonstrate our attack on the constant-time reference implementation of Classic McEliece in a single-trace setting, using an STM32L592 ARM processor.Our result stresses the necessity of properly protecting highly structured code-based schemes such as McEliece against side-channel leakage
Leading Degree: A Metric for Model Performance Evaluation and Hyperparameter Tuning in Deep Learning-Based Side-Channel Analysis
Get PDFSide-channel analysis benefits a lot from deep learning techniques, which assist attackers in recovering the secret key with fewer attack traces than before, but it remains a problem to precisely measure deep learning model performance, so as to obtain a high-performance model. Commonly used evaluation metrics for deep learning like accuracy and precision cannot well meet the demand due to their deviation in side-channel analysis, and classical evaluation metrics for side-channel analysis like guessing entropy, success rate and TGE1 are not generic because they effectively evaluate model performance in only one of the two situations: whether models manage to recover the secret key with given attack traces or not, and not efficient because they need to be performed multiple times to counteract randomness. To attain an effective generic side-channel evaluation metric, we investigate the deterministic component of power consumption, find that the elements of score vector under a key follow a linearly transformed chi-square distribution approximately, and some wrong key hypotheses usually with top scores provide great assistance in model performance evaluation, and finally we propose a new metric called Leading Degree (LD) as well as its simplified version LD-simplified for measuring model performance, which offers similar accuracy but much better generality and efficiency compared with the classical side-channel benchmark metric TGE1, and offers similar generality and efficiency but significantly better accuracy compared with recently proposed sidechannel metrics like Label Correlation and Cross Entropy Ratio. LD/LD-simplified can be easily deployed in early stopping to avoid overfitting phenomena, and we build a bridge between LD/LD-simplified and TGE1, by observing an exponential relationship, which significantly shortens the estimating time for TGE1. At last, we apply LD as a reward function to better solve the reward function design problem in reinforcement learning-based model hyperparameter tuning of side-channel analysis, and obtain better CNN model architectures compared with the state-of-the-art models obtained by previous hyperparameter tuning methods
Accelerating EdDSA Signature Verification with Faster Scalar Size Halving
Get PDFThis paper establishes that the extended Euclidean algorithm (EEA) implemented in a division-free manner is faster than the Lagrange algorithm with a similar level of optimization when it comes to halving the size of scalars found in the equations of elliptic curve signature verification. Our implementation results show that our EEA based method achieves roughly 4x speed-up for generating half- size scalars used in EdDSA. For the first time ever, EEA generated half-size scalars are used for verification of individual Ed25519 signatures yielding timing results that outperform ed25519-donna, a highly optimized open source implementation, by 16.12%. We also propose a new randomization method applied with half-size scalars to batch verification of Ed25519 signatures for which we report speed-ups compared to the well-known Bernstein et al. method for batch sizes larger than six, specifically, our method achieves 11.60% improvement for batch size 64
Algebraic Linear Analysis for Number Theoretic Transform in Lattice-Based Cryptography
Get PDFThe topic of verifying postquantum cryptographic software has never been more pressing than today between the new NIST postquantum cryptosystem standards being finalized and various countries issuing directives to switch to postquantum or at least hybrid cryptography in a decade. One critical issue in verifying lattice-based cryptographic software is range-checking in the finite-field arithmetic assembly code which occurs frequently in highly optimized cryptographic software. For the most part these have been handled by Satisfiability Modulo Theory (SMT) but so far they mostly are restricted to Montgomery arithmetic and 16-bit precision. We add semi-automatic range-check reasoning capability to the CryptoLine toolkit via the Integer Set Library (wrapped via the python package islpy) which makes it easier and faster to verify more arithmetic crypto code, including Barrett and Plantard finite-field arithmetic, and show experimentally that this is viable on production code
Research on L1 literature education teachers : A scoping review
Get PDFAusgehend von der Annahme, dass professionelles Leher*innenhandeln das Lernen von Schüler*innen maßgeblich beeinflusst, sind in den letzten Jahren auch in der Deutschdidaktik zahlreiche Arbeiten entstanden, die unterschiedliche Facetten des Wissens und Könnens von Deutschlehrkräften untersuchen. Unter anderem angeregt durch groß angelegte Förderlinien, wie etwa die Qualitätsoffensive Lehrerbildung, ist vor allem in den letzten gut zehn Jahren ein besonderer Zuwachs an Forschungsarbeiten in diesem Feld zu verzeichnen. Entsprechend scheint es geboten, einmal mehr nach dem Stand und möglichen Perspektiven deutschdidaktischer Lehrer*innenforschung zu fragen. Angesichts der Fülle existierender Studien betrachtet der vorliegende Beitrag dabei nicht die deutschdidaktische Forschung in Gänze, sondern fokussiert mit der Literaturdidaktik einen Teilbereich der Disziplin. Um die bisherigen Forschungsbeiträge zu sortieren, geht die Arbeit von einem kompetenzorientierten Verständnis von Lehrer*innenprofessionalität aus und kartiert bisherige Studien im Rahmen eines Scoping Reviews basierend auf einer Kompetenzmodellierung von Blömeke et al. (2015). Ziel des Beitrags ist es, Stärken, Herausforderungen und daraus erwachsende Desiderate literaturdidaktischer Professionalisierungsforschung zu beschreiben.Based on the assumption that professional teacher competence has a significant impact on student learning, numerous studies have been conducted that examine various facets of the knowledge and skills of German teachers. Stimulated by large-scale funding programs, there has been an increase in research in this field, especially in the last ten years. Accordingly, it seems appropriate to ask about the status and possible perspectives of L1 German teacher research within a scoping review. Given the number of studies that have emerged in the meantime, the present study does not consider research on teaching German in its entirety, but focuses only on one specific domain: the research on literature education. The study starts from a competence-based understanding of teacher professionalisation and maps previous studies based on a competence model by Blömeke et al. (2015). Consequently, the aim of this article is to describe the strengths, challenges and resulting desiderata of the research on professionalization in literature education
When life is but a dream: Does transliminality predict continuity of thought across the sleep-wake cycle?
Get PDFPeople with fantasy proneness and dispositions towards absorption and hypnotizability encounter waking thoughts that are particularly bizarre or dreamlike in nature. This suggests not only a continuity between dreaming and waking thoughts—what we refer to as continuity of thought—but perhaps stable individual differences in continuity of thought. The personality trait transliminality, which has been linked with increased awareness of subliminally-presented material, may underlie these dispositions and thus shows unique promise for predicting continuity of thought. In a sample of undergraduate students, we measured transliminality using the Revised Transliminality Scale (RTS) and then used experience sampling to capture the phenomenological qualities of dreaming and waking thoughts for one week. We examined evidence for continuity of thought across the sleep-wake cycle, examined the connection between transliminality and dreamlike thoughts in wakefulness, and assessed whether transliminality predicts greater overall continuity of thought. Results showed transliminality was unrelated to overall continuity of thought, however further exploratory analyses showed transliminality predicted greater continuity in bizarreness of thought—though this effect did not hold up after controlling for multiple comparisons. Moreover, transliminality was positively associated with waking thoughts that were more bizarre, interesting and novel. Overall, this work advances understanding on how personality may relate to phenomenology of thought, and opens the door for future research to assess how these personality-phenomenology relations may impact wellbeing, creativity, or behavior more generally.
Précis of Neuroethics
Get PDFThe main message of Neuroethics is that neuroscience forces us to reconceptualize human agency as marvelously diverse and flexible. Free will can arise from unconscious brain processes. Individuals with mental disorders, including addiction and psychopathy, exhibit more agency than is often recognized. Brain interventions should be embraced with cautious optimism. Our moral intuitions, which arise from entangled reason and emotion, can generally be trusted. Nevertheless, we can and should safely enhance our brain chemistry, partly because motivated reasoning crops up in everyday life and in the practice of neuroscience itself. Despite serious limitations, brain science can be useful in the courtroom and marketplace. Recognizing all this nuance leaves little room for anxious alarmism or overhype and urges an emphasis on neurodiversity. The result is a highly opinionated tour of neuroethics as an exciting field full of implications for philosophy, science, medicine, law, and public policy
Response to commentators of Neuroethics
Get PDFIn this reply, I address questions and concerns about Neuroethics raised by a formidable cast of commentators: Amanda Evans, Tyler Fagan, Jonathan Pugh, Daniel Moseley, and Adina Roskies. Their insightful commentaries cover most, if not all, topics within the book, namely: neuroscientific challenges to free will, motivated reasoning and the replication crisis, the brain disease model of addiction, moral responsibility and autonomy in mental disorder, valid consent for brain interventions, and enhancement of moral and cognitive capacities through neurotechnologies
Designing an ESAP course on sustainability with resources in mind : From theory to practice
Get PDFIn diesem Beitrag wird ein nachhaltiger Ansatz zur Kursentwicklung vorgestellt, der am Zentrum für Fremdsprachenausbildung der Ruhr-Universität Bochum verfolgt wird. Dieser Ansatz berücksichtigt die Notwendigkeit einer kontinuierlichen Überarbeitung von Fachsprachenkursen für akademische Zwecke. Dieser ressourcenintensive Prozess wird oft als nicht nachhaltig und ineffizient angesehen, ist aber für die Qualität der Lehre unerlässlich. Der Beitrag schlägt vor, wie der Prozess optimiert und ressourcenschonend gestaltet werden kann.
Gleichzeitig ist Nachhaltigkeit das Hauptthema des hier vorgestellten Fachsprachenkurses. Indem den Studierenden eine Plattform geboten wird, auf der sie ausgewählte Nachhaltigkeitsprobleme an ihrer eigenen Universität diskutieren und zu lösen versuchen, wollen die Kursentwickler*innen einen anregenden und sinnvollen Rahmen für den Erwerb fachsprachlicher Kompetenzen und die Erweiterung von Wissen und Verständnis für aktuelle Nachhaltigkeitsfragen schaffen. Die vorliegende Kursdarstellung dient als Beispiel dafür, wie die Ziele der Bildung für nachhaltige Entwicklung und der Nachhaltigkeit des Lehrens und Lernens im lokalen Kontext aufgegriffen und in der Fremdsprachenausbildung an Hochschulen umgesetzt werden können.This paper presents a sustainable approach to course development that is being pursued at the University Language Centre at the Ruhr University Bochum. In order to maintain the quality of teaching, courses for specific academic purposes need to be continuously revised. The article suggests ways in which this resource-intensive process, often seen as unsustainable and inefficient, can be optimised and designed to make the most efficient use of available resources. The model course used to illustrate the approach has sustainability as its main theme. By providing a platform for students to discuss and attempt to solve selected sustainability problems at their own university, the course developers aim to create a stimulating and meaningful framework for the acquisition of specialised language skills and the expansion of knowledge and understanding of current sustainability issues. Finally, this course serves as an example of how the goals of Education for Sustainable Development and sustainability of teaching and learning can be addressed in the local context and implemented in university language teaching.