Analysis of encryption schemes in modern ransomware

In the past few years, activity of ransomware increased. As new variants and families of ransomware are developed, security systems have to keep up. Well designed encryption system is at the heart of ransomware and even a small mistake in the algorithm can break it. This paper analyzes 10 ransomware samples from various families. The goal of the analysis is to describe encryption schemes used in current ransomware. This includes key generation and storage, symmetric and asymmetric ciphers and their chosen implementation

Full-scale magnetic, microstructural, and physical properties of bilayered CoSiB/FeSiB ribbons

The paper is devoted to the detailed analysis of microstructural and magnetic properties of the as-quenched bilayered Co72.5Si12.5B15/Fe77.5Si7.5B15 ribbons prepared by the planar flow casting (PFC) method with single crucible. The interface between both amorphous Co- and Fe-based layers is not uniform and its thickness ranges from 0.5 to 6 μm over the whole ribbon length. Dependences of mechanical characteristics on the ribbon thickness show increase in Young’s modulus from 140 to 170 GPa and decrease in microhardness from 18 to 13 GPa, when measured from the wheel (Co) to air (Fe) side. By fixing the coiled ribbon on the planar sample holder a uniaxial magnetic anisotropy with the out-of-plane and the in-plane easy axis is induced on the air and wheel side, respectively. Bulk magnetic properties confirm that perpendicular anisotropy observed on the air side becomes stronger as getting deeper under the surface and overlaps the in-plane anisotropy from the wheel side. This is in good agreement with Mössbauer measurements. Magnetic characteristics (surface hysteresis loops and domains, bulk hysteresis loops and thermomagnetic curves) of the bilayered samples were further compared with the single-layered CoSiB and FeSiB alloys.Web of Science58169268

Web usage analysis of Pillar 3 disclosed information by deposit customers in turbulent times

Market discipline has been a scrutinized area since the last financial crisis in 2008. Regulators strengthened their role particularly through Pillar 3 in Basel III. However, there are still some aspects of market discipline that deserve special attention to avoid future failures. This study focuses on the analysis of the interest and behaviour of deposit stakeholders based on website data dedicated to disclosures of commercial bank in Slovakia during and after turbulent times (period 2009–2012). The data consists of log files, and web mining techniques were applied (the modelling of web user behaviour in dependence on time - based on the proposals of the authors). The results show that also in turbulent times, stakeholders’ interest in Pillar 3 disclosures is low (in line with (Munk, Pilkova, Benko, & Blažeková, 2017)) and the highest interest was identified for the Pricing List category. After turbulent times, Pillar 3 categories (Pillar 3 related information and Pillar 3 disclosures) have weak interest, with peaks at the beginning of the year, and the highest increase was in the Business Conditions category. The results suggest that the enhancement of interest of key stakeholders in disclosures inevitably requires changes to deliver sufficient disclosure data structures and to design a disclosure policy that fulfils regulatory expectations. © 2021 The AuthorsScientific Grant Agency of the Ministry of Education of the Slovak Republic (ME SR); Slovak Academy of Sciences (SAS) [VEGA-1/0776/18, VEGA-1/0821/21]Slovenská Akadémia Vied, SAV: VEGA-1/0776/18, VEGA-1/0821/2

Forest leaf litter beetles of Taiwan: first DNA barcodes and first insight into the fauna

We report the publication of 953 DNA barcodes of forest leaf litter beetles from central Taiwan, in total representing 334 spe- cies of 36 beetle families. This is the first bulk of data from the Taiwanese Leaf Litter beetles project focused on uncovering the under-explored diversity of leaf litter beetles across Taiwan. Based on these data, we provide the first records of the following taxa for Taiwan: family Sphindidae (genus Aspidiphorus Ziegler, 1821); tribes Trichonychini, Ctenistini, and Bythinoplectini (all Staphylinidae: Pselaphinae); genera Gyrelon Hinton, 1942, Thyroderus Sharp, 1885, Cautomus Sharp, 1885 (all Cerylonidae), Dermatohomoeus Hlisnikovský, 1963 (Leiodidae), Paraploderus Herman, 1970 (Staphylinidae: Oxytelinae), Thinocharis Kraatz, 1859 (Staphylinidae: Paederinae), Cephennodes Reitter, 1884, Napoconnus Franz, 1957 (both Staphylinidae: Scydmaeninae), Bicava Belon, 1884 (Latridiidae), Otibazo Morimoto, 1961, Seleuca Pascoe, 1871 and Acallinus Morimoto, 1962 (all Curculioni- dae); species Oodes (Lachnocrepis) japonicus (Bates, 1873) (Carabidae: Licininae), Drusilla obliqua (Bernhauer, 1916) (Staphylin- idae: Aleocharinae) and Coccotrypes advena Blandford, 1894 (Curculionidae: Scolytinae). The records of Anapleus Horn, 1873 (Histeridae) and Batraxis Reitter, 1882 (Staphylinidae: Pselaphinae) have been confirmed. The male of Sivacrypticus taiwanicus Kaszab, 1964 (Archeocrypticidae) is described for the first time. Gyrelon jenpani Hu, Fikáček & Matsumoto, sp. nov. (Cerylon- idae) is described, illustrated, and compared with related species. DNA barcodes associated larvae of 42 species with adults, we are concisely illustrating some of these: Oodes japonicus, Perigona cf. nigriceps Dejean, 1831 (both Carabidae), Ptilodactyla sp. (Ptilodactylidae), Maltypus ryukyuanus Wittmer, 1970 (Cantharidae), Drusilla obliqua, Myrmecocephalus brevisulcus (Pace, 2008), Diochus sp., Mimopinophilus sp. (all Staphylinidae), Stelidota multiguttata Reitter, 1877, Lasiodites inaequalis (Grouvelle, 1914) (both Nitidulidae), Lagria scutellaris Pic, 1910, and Anaedus spinicornis Kaszab, 1973 (both Tenebrionidae). We also report the first cases of Rickettsia infections in Scydmaeninae and Pselaphinae. All data (sequences, metadata, and voucher photos) are made public in BOLD database and in a Zenodo Archive

NATO Advanced Research Workshop on Properties and Applications of Nanocrystalline Alloys from Amorphous Precursors

Metallic (magnetic and non-magnetic) nanocrystalline materials have been known for over ten years but only recent developments in the research into those complex alloys and their metastable amorphous precursors have created a need to summarize the most important accomplishments in the field. This book is a collection of articles on various aspects of metallic nanocrystalline materials, and an attempt to address this above need. The main focus of the papers is put on the new issues that emerge in the studies of nanocrystalline materials, and, in particular, on (i) new compositions of the alloys, (ii) properties of conventional nanocrystalline materials, (iii) modeling and simulations, (iv) preparation methods, (v) experimental techniques of measurements, and (vi) different modern applications. Interesting phenomena of the physics of nanocrystalline materials are a consequence of the effects induced by the nanocrystalline structure. They include interface physics, the influence of the grain boundaries, the averaging of magnetic anisotropy by exchange interactions, the decrease in exchange length, and the existence of a minimum two-phase structure at the atomic scale. Attention is also paid to the special character of the local atomic ordering and to the corresponding interatomic bonding as well as to anomalies and particularities of electron density distributions, and to the formation of metastable, nanocrystalline (or quasi-crystalline) phases built from exceptionally small grains with special properties. Another important focus of attention are new classes of materials which are not based on new compositions, but rather on the original and special crystalline structure in the nanoscale

Data advance preparation factors affecting results of sequence rule analysis in web log mining

One of the main tasks of web log mining is discovering patterns of behaviour of portal visitors. Based on the found patterns of users behaviour, which are represented by sequence rules it is possible to modify and improve the web page of an organisation. This article aims at finding out by means of an experiment to what degree it is necessary to realize data preparation for web log mi- ning and it aims also at specifying inevitable steps for obtaining valid data from the log file. Results of the experiment are very important for the portal, which is regularly analysed and modified, since they can prove correctness of individual steps at analysis, or through an identification of “usele- ss” steps they can make the advance preparation of data simpler. These results show that data cleaning from crawlers accesses has a significant impact on the quantity of extracted rules only in case, when we use the method of paths completion. On the contrary, the impact on the reduction of the portion of inexplicable rules as well as the impact on the quality of extracted rules in terms of their basic characteristics was not proved. Paths completing was proved crucial in data prepa- ration for web log mining. It was proved that paths completing has a significant impact both on the quantity and the quality of extracted rules. However, it was prov ed that allowing the used browser upon identifying sessions has neither any significant impact on the quantity nor on the quality of extracted rules. There exist a number of models for identification of users sessions, which are cru- cial in data preparation, however, there e xists also a method, which identifies them expressly. Our next goal is to additionally programme this functionality into the existing system and analyse various parameters of individual methods of identification of sessions compared with the reference direct identification. It also mentions the necessity to pay attention to the analysis of web logs in the real time and to reduce the time needed for the advance preparation of these logs and at the same time to increase accuracy of these data depending on the time of their collection

(GTG)5-PCR fingerprinting of lactobacilli isolated from cervix of healthy women

A group of lactobacilli isolated from the cervix of 31 healthy women was characterized by (GTG)(5)-polymerase chain reaction (PCR) fingerprinting in order to evaluate this method for identification of vaginal lactobacilli. Obtained fingerprints were compared with profiles available in an in-house database of the CCM bacteria collection covering type and reference strains of multiple lactic acid bacteria including lactobacilli. Selected strains representing individual clusters were further identified by pheS gene sequencing. In total, six lactobacillus species were found among lactobacilli isolated from the cervix of healthy women. The (GTG)(5)-PCR method identified Lactobacillus gasseri (11 strains), Lactobacillus fermentum (one), and some of the Lactobacillus jensenii strains (eight out of 11), but failed to identify the remaining strains, including the Lactobacillus crispatus (18), Lactobacillus mucosae (one), and Lactobacillus vaginalis (one) species. L. jensenii strains were distributed over two fingerprint clusters. The majority of samples was dominated by one (GTG)(5)-PCR type. The rep-PCR fingerprinting using the (GTG)(5) primer allowed straightforward identification of many, but not all, isolates. This method has been shown to be a useful tool for fast screening and grouping of vaginal lactobacilli, but its combination with another identification method is needed to obtain reliable identification results. In addition, Lactobacillus acidophilus was not shown to be the most common inhabitant of the female genital tract as generally assumed