Attacking and Defending Masked Polynomial Comparison for Lattice-Based Cryptography

In this work, we are concerned with the hardening of post-quantum key encapsulation mechanisms (KEM) against side-channel attacks, with a focus on the comparison operation required for the Fujisaki-Okamoto (FO) transform. We identify critical vulnerabilities in two proposals for masked comparison and successfully attack the masked comparison algorithms from TCHES 2018 and TCHES 2020. To do so, we use first-order side-channel attacks and show that the advertised security properties do not hold. Additionally, we break the higher-order secured masked comparison from TCHES 2020 using a collision attack, which does not require side-channel information. To enable implementers to spot such flaws in the implementation or underlying algorithms, we propose a framework that is designed to test the re-encryption step of the FO transform for information leakage. Our framework relies on a specifically parametrized t-test and would have identified the previously mentioned flaws in the masked comparison. Our framework can be used to test both the comparison itself and the full decapsulation implementation.

Logical Mechanisms of Comprehending Culture: An Experience of a Theoretical and Methodological Research

В статье предложена конкретизация методов постижения культуры, отражающая онтологию самой культуры. Несмотря на разнообразие теорий, в культурологии отмечается недостаточная конкретизация принципиальных оснований, необходимых для формирования методов постижения различных аспектов культуры как реальности. Целью явилось определение совокупности парадигм методических представлений, с которыми связано логическое постижение культуры. Источником исследования послужили различные представления культуроцентризма: как социальной стратегии (В. С. Библер, А. Я. Флиер), как научно-исследовательской программы (Г. Риккерт), как мировоззренческой позиции (М. С. Каган, Ю. В. Ларин). Исследование осуществлено в два этапа: через акт сравнения конкретизированы основания для формирования методологий логики, диалектики и антиномии, затем показана сфера применимости каждой области методов в отношении культуры. Полученные результаты важны для разработки общих и специальных методологий постижения культуры. Cultural centrism is a concept that considers culture as an ontological reality. The fundamental foundations necessary for the formation of methods of comprehending various aspects of culture as reality are insufficiently specified. The aim of the study is to determine the set of paradigms of methodological concepts that are associated with the logical comprehension of culture. The sources of the study were various representations of cultural centrism: as a social strategy, as a research program, as a worldview position. The methodological foundations for comprehending culture should reflect its ontology, multidimensionality and metalogical complexity. The study was carried out in two stages: through the act of comparison, the grounds for the formation of methodologies of logic, dialectic and antinomy were specified, then the scope of applicability of each methodology in relation to culture was shown. The methodological basis for comprehending the ontology of culture was developed based on the positions of cultural centrism. The research methods are differentiated analysis and conceptual modeling within the framework of a system-structural approach to the object of research. The objectivity of the methodology requires that the logic of cognition be consistent with the nature of the perceived reality. The main methodological element of the cognizing act is the implementation of a logical comparison operation, which can be resolved in three ways, forming the methods of logic, dialectic and antinomy of culture. The logic of culture coincides with its morphology, it reflects the existence and development of objective forms of culture (symbolic, normative, axiological and objective representations, enshrined in the corresponding theories of cultural genesis, are fundamental ones). The dialectic of culture repeats personal inculturation and cultural creation. The antinomy of culture reflects the inconsistency of the ontological reality of culture, which unambiguously and inseparably connects the subject and the object of culture. This allows us to consider in unity all the particular concepts of describing culture’s specific reality (nature-centric, sociocentric, anthropocentric and theocentric) and all the types of culture’s actualization (objective, normative, axiological and symbolic). As a result, the concretization of methods of comprehending culture is proposed. The concretization reflects the ontology of culture itself. The results obtained are promising for the development of general and specific methodologies for comprehending culture.

The Impact of Selected Biofuels on the Skoda Roomster 1.4TDI Engine’s Operational Parameters

Road transport is increasing all around the globe and biofuels have come to the forefront of public interest. According to Article 3, Directive 2009/28/EC, each member state has to ensure that an energy share from renewable sources in all forms of transportation reaches at least 10% of the final consumption of energy in transportation until 2020. The blending of biofuels is one of the methods available to member states to meet this target and it might even be expected to be a main contributor. This article analyses and compares selected biofuels, their chemical properties and their influence on engine operational parameters. The operational parameters of the diesel engine of the Skoda Roomster 1.4 TDI were measured on a chassis dynamometer according to the NEDC driving cycle, and pure diesel fuel, HVO and a blend of fuels (diesel fuel, HVO and butanol) were used for comparison. Operation on biofuels shows a slight decrease in performance parameters up to 10% and an increase in emission production (especially CO in the case of D50H30B20). Positive influences of biofuels were proven with a decrease in exhaust gas opacity and particulate matter production, up to 50% in the case of D50H30B20.

Optical Comparison Operation for 8-Bit QPSK-Modulated Signal by Using Serially-Cascaded Delay Line Interferometer

An all-optical comparator is desirable to realize large-capacity, fully-transparent, and energy-efficient communication systems, as it is considered to be a fundamental component to perform most of the operations, including packet switching, label recognition, error detection and correction, and so on. However, most of the previous studies have been confined to the on–off keying (OOK) modulation format, not phase-shift keying (PSK) modulation. In this paper, the author provides a novel optical comparator designed for quadrature PSK (QPSK)-modulated signal, which comprises a code word with 8-bit length, using a serially-cascaded delay line interferometer. The proposed comparator yields constellations having the information of a Hamming distance based on the designed code, when several patterns of QPSK signal are injected into the comparator. The paper experimentally demonstrates the feasibility of the optical comparison operation for 8-bit QPSK-modulated return-to-zero (RZ) signal at 10 Gbaud.