Ruhr-Universität Bochum (RUB): Open Journal Systems
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Poster: A microarchitectural signals analysis platform to craft Hardware Security Counters
Get PDFDetecting malicious software or hardware behavior during the operation of a computer system requires observables from one or more abstraction layers of the system. However, this abstraction tends to limit the ability to detect behavioral deviations, especially for attack classes that exploit vulnerabilities very close to the target hardware. Conversely, too low a level of abstraction tends to significantly increase the complexity of the system model, and therefore poses a number of difficulties for the extraction and selection of relevant observables for a given class of attack.In particular, processor performance counters have been used as an indirect means of observing microarchitecture behavior and detecting software attempting to exploit hardware vulnerabilities. In order to improve the various detection methods, we propose the construction of hardware metrics designed from the outset for security, by studying the correlation between signals from the microarchitecture and the various classes of attack in the literature, targeting both usual and industrial systems. By extension, this work aims to detect attacks originating from hardware Trojans, the latter having the effect of changing the behavior of a given microarchitecture
Cube Attacks with Elimination Strategy: Key Recovery Attacks on Trivium
No full textIn this paper, we present a novel framework for cube attacks named cube attacks with elimination strategy. The core idea is to find specific key conditions and cubes such that their superpolies under these key conditions can be efficiently computed. By recovering these conditional superpolies, we can solve the corresponding equation system and thereby retrieve key information. If a sufficient number of such key conditions can be found, the attack can be extended to a larger key space. To apply this framework in practical attacks, we propose the following techniques.First, we propose a nested coefficient solver that combines variable substitution and symbolic computation to efficiently recover superpolies, and present the conditional monomial prediction technique to rapidly recover conditional superpolies. Second, by combining numeric mapping with monomial prediction techniques, we propose an automated cube search algorithm that is capable of generating a large number of good cubes for attacks. Finally, we develop two kinds of testing methods, which are used to efficiently extract substantial key information from large-scale equation systems.To illustrate the power of our techniques, we apply them to Trivium. As a result, for 840 rounds of Trivium, a practical key recovery attack is mounted with complexity below 255 and a success rate 77.8%. For 845 rounds, we present a practical key recovery attack with complexity below 256 and a success rate 98.1% for 280 x 59.1% keys. For 855 rounds, we present a theoretical weak-key recovery attack for 274 keys. To the best of our knowledge, these are the best practical and theoretical attacks on Trivium. The improvements in the number of rounds reached are 13 for practical attacks and 4 for theoretical attacks, respectively
Leaded Copper Crescent-Shaped Objects and a Brass Ring from Medieval Gao, Mali
No full textCopper-related metal artefacts and ingots are prominent metal objects of the Trans-Saharan trade route, providing a nexus between producers and consumers often separated by vast distances. The role of Gao in southern Mali as a major transit point of this trade is archaeologically and historically well established, within the framework of other Medieval trade towns. However, the study of Gao’s metallurgical heritage is not fully explored and is full of potential. Of particular interest are the hundreds of crescent-shaped metal objects found across the different parts of Gao, but not encountered elsewhere. We present a pilot study on five crescent fragments and one brass ring from Medieval Gao, offering new compositional and isotopic data. It is unlikely that these objects were re-melted or recycled, given the frequent presence of sulphide inclusions in them. The results show that the crescent-shaped objects are heavily leaded copper and retain their as-cast texture, making a functional use unlikely. Their composition is either due to a possible mixing of lead and copper metal, or the smelting of multi-metallic ores where different batch compositions result in different concentrations in lead, antimony and arsenic within the dominant copper metal. The lead isotope data, presented here for the first time, confirm general statements made earlier for a similar set of artefacts from Gao, arguing that the metal is isotopically consistent with lead ores from Tunisia as well as being similar to several artefacts from Nigeria, in particular Igbo Ukwu. In the absence of a comprehensive database of regional copper ore data and the long-distance trade of lead across the Sahara, a firm assignment of geological origin of the metal from Gao’s crescent-shaped objects remains elusive
Attention and collective interests in artificial intelligence: In search of a regulatory framework
No full textRecent debates frequently refer to artificially intelligent systems as agents, sometimes referencing their capacity for attention. Yet, the self-determination associated with agency requires a form of attention that is not yet present in artificial systems. It is thus worth asking how these artificial systems achieve the results they do. In this paper we explore the role of attention in artificial intelligence and argue that we should understand these systems as collective agents comprising the software developers, creators of training data, and users. Given this new understanding of artificial intelligence, we suggest a novel method for regulating these technologies: a corporate law approach. By treating artificially intelligent systems as corporate subcontractors, we can better protect both users and the broader public
Investigating Pre-Columbian Gold and Copper in Costa Rica – Ores, Mines and Artefact Production
No full textThe wealth of pre-Columbian gold, copper and guanín (an alloy consisting mainly of gold and copper; also tumbaga) artwork of Costa Rica suggests that exploitation of its abundant ore deposits goes back way before the Spanish conquest. The name of Costa Rica itself, in fact alludes to the large numbers of golden metal objects worn by the indigenous peoples upon arrival of the conquistadors. Up to now, however, very little is known about pre-Columbian mining in the country or the raw material provenance of these artefacts. In a transdisciplinary project, we aim to reconstruct the metallurgical process chain by combining (mining) archaeological research with geochemical analysis of local ores and metal artefacts using a combination of different techniques. We identified four major gold and copper districts with different mineralisation types, which are the focus of our fieldwork-based research. They are surveyed for potential signs of pre-Columbian metal production and sampled for ores and their processing remains. On the other side of the process chain, we focus on the metal artefacts in museum collections. They are systematically registered in a database, which serves as a basis to identify correlations with the geochemical signatures of the artefacts, and to retrace potential links to possible areas of origin or different workshops. Once the necessary basic data have been collected, we will focus on economic and socio-cultural aspects of metal production and circulation. The results from Costa Rica will be put into perspective of New World early metallurgy and can provide a starting point for future research between Mesoamerica and the Isthmo-Colombian region.
A versioning of the article was necessary because a literature citation in the reference list had to be revised
Ibn Taymiyya’s Critique of Christianity: An Extension of Intra-Islamic Debates on Qurʾanic Hermeneutics
No full textThis essay shows how the Ḥanbalī scholar Ibn Taymiyya (d. 728/1328) extends to Christianity what is essentially an intra-Islamic controversy about qurʾanic hermeneutics, itself part of a wider debate on the conflict between reason and revelation. The essay argues that in order to grasp Ibn Taymiyya’s critique of Christianity, one must understand his position on three key issues: (1) his redefinition of qurʾanic exegesis from an open-ended scholarly enterprise into a part of the body of prophetic knowledge, transmitted by the pious ancestors; (2) his views on the agreement of reason and revelation, which he sees as complementary paths to the same truth; and (3) his denunciation of a hermeneutical approach that deflects the intended meaning of the sacred text in order to justify unorthodox views or simply to sow doubt and division, a practice he then attributes to Christians
Journeys to Resilience: Becoming a Prepper as a Process of Conversion
No full textThe article examines the phenomenon of “prepping” from the perspective of conversion research. Based on a qualitative content analysis of postings from a big prepper online forum in the U.S., it explores the causes and modalities of adopting prepping as a lifestyle. The causes include biographical instances, experiences of disaster and emergency, reports from others and a general sense of threat. As to the modalities, the transition into prepping appears to take place gradually, although disruptive incidents may serve as important triggers for the decision to become a prepper. By interpreting the adoption of prepping as a form of secular conversion, the article aims to contribute to recent discussions on religious-secular competition and provides a test case of how religious studies may contribute to the analysis of non-religious worldviews and lifestyles
Wisdom and Virtue Ethics in the Cairo Genizah: The Intersection of Jewish and Islamic Moral Education
No full textIn medieval and early modern Jewish circles, poetry functioned as an important medium through which hortatory reminders were expressed and spiritual thought preserved. Much of the didactic material that can be discerned from the Judaeo-Arabic poetry fragments does not make direct biblical, or for that matter, quranic references, albeit both are represented to varying degrees here. Two verses from the Qur’an are partially quoted as well as echoes of the Book of Proverbs (Old Testament) in several of the poetry verses. Poetic references which promote the good treatment of others, keeping positive in difficult circumstances, and similar moral values and virtues are scattered throughout these fragments, espousing a general religious sentiment that is incontrovertibly aligned to Jewish and Islamic values and promoted by the sacred texts of each respective tradition. Religious wisdom distilled in such poetry on a few occasions is even made with direct reference to Islamic phrases that have distinct relations to Jewish themes. An appeal to emotions is also evoked to heighten the appeal of the teachings. This paper will attempt to make a connection between such fragments and Islamic textual sources to argue that the values which the Jewish authors were promoting were often congruent with the values espoused by the Muslim society in which they were composed. However, on occasion, there seems to be selective use of Islamic sources, which bolsters the theory that only those parts which align with a positive Jewish identity were included on account of their authors being Jewish
Observations on the BayesianKeySearch with Applications to Simon and Simeck
No full textIn CRYPTO 2019, Gohr pioneered the integration of machine learning with differential cryptanalysis, demonstrating that differential-neural distinguishers can outperform classical techniques in distinguishing attacks. He also introduced a novel key-recovery strategy based on Bayesian optimization, termed BayesianKey- Search, enhancing key recovery for Speck32/64. However, the impact of parameter selection on the complexity and success probability of key-recovery attack using BayesianKeySearch remains underexplored.This paper investigates the impact of parameter selections on key-recovery effectiveness. Gohr’s key-recovery attack involves two stages, each using a cutoff value to filter candidate guesses for the last subkey and second-to-last subkey. Previous works selected these cutoffs independently. We propose connecting these cutoff selections, enhancing coordination between stages and improving the attack’s complexity and success probability.Applying our parameter optimization, we enhance the single-key recovery attacks on 16-round Simon32/64, 16-round and 17-round Simeck32/64, achieving higher success rates and lower time complexities compared to previous works. Additionally, for related-key differential-neural attacks on Simon32/64, we exploit both single-key and related-key features from cross-paired ciphertexts, developing advanced neuraldistinguishers for up to 13 rounds. Using these neural-distinguishers combined with carefully selected classical differentials, we devise an 18-round related-key recovery attack on Simon32/64. Our results validate the practical effectiveness of the proposed strategies and are expected to contribute to the advancement of machine learningaided cryptanalysis