Flexible and Robust Privacy-Preserving Implicit Authentication

Implicit authentication consists of a server authenticating a user based on the user's usage profile, instead of/in addition to relying on something the user explicitly knows (passwords, private keys, etc.). While implicit authentication makes identity theft by third parties more difficult, it requires the server to learn and store the user's usage profile. Recently, the first privacy-preserving implicit authentication system was presented, in which the server does not learn the user's profile. It uses an ad hoc two-party computation protocol to compare the user's fresh sampled features against an encrypted stored user's profile. The protocol requires storing the usage profile and comparing against it using two different cryptosystems, one of them order-preserving; furthermore, features must be numerical. We present here a simpler protocol based on set intersection that has the advantages of: i) requiring only one cryptosystem; ii) not leaking the relative order of fresh feature samples; iii) being able to deal with any type of features (numerical or non-numerical). Keywords: Privacy-preserving implicit authentication, privacy-preserving set intersection, implicit authentication, active authentication, transparent authentication, risk mitigation, data brokers.Comment: IFIP SEC 2015-Intl. Information Security and Privacy Conference, May 26-28, 2015, IFIP AICT, Springer, to appea

A simple and effective method for ultrastructural analysis of mitosis in Drosophila S2 cells

© 2016 The AuthorsThe Drosophila S2 tissue culture cells are a widely used system for studies on mitosis. S2 cells are particularly sensitive to gene silencing by RNA interference (RNAi), allowing targeted inactivation of mitotic genes. S2 cells are also well suited for high-resolution light microscopy analysis of mitosis in fixed cells, and can be easily immunostained to detect mitotic components. In addition, S2 cells are amenable to transformation with plasmid encoding fluorescently tagged mitotic proteins, allowing in vivo analysis of their behavior throughout cell division. However, S2 cells have not been widely used for transmission electron microscopy (TEM) analysis, which provides ultrastructural details on the morphology of the mitotic apparatus that cannot be obtained with high-resolution confocal microscopy. Here, we describe a simple method for the ultrastructural analysis of mitosis in Drosophila S2 cells. • Our method, which involves fixation and sectioning of a cell pellet, provides excellent preservation of mitotic structures and allows analysis of a higher number of mitotic divisions per sample, compared to correlative light-electron microscopy.• Dividing cells are randomly oriented within the pellet and are sectioned along different planes, providing all-around information on the structure of the mitotic apparatus

SOCIALIZATION OF DIGITAL EDUCATION THROUGH THE ENHANCEMENT OF REMOTE TESTING

The article is based on the results of analysis of educational subjects for bachelors of the 1st, 2nd, and 3d years of education in the socio-adapted system of remote training for various management and economic specialization profiles. According to the conducted study, the course units have been determined for which remote training and controlled assessment are justified, the results of electronic testing of students have been summarized, the dynamics of the results has been revealed, the directions of enhancement of testing and testing material development technologies have been shown, the socio-adapted types of test questions have been highlighted, and examples of typical test questions have been provided, recommendations on the method of presentation of educational material have been formulated

Influence of long-range dipolar interactions on the phase stability and hysteresis shapes of ferroelectric and antiferroelectric multilayers

Phase transition and field driven hysteresis evolution of a two-dimensional Ising grid consisting of ferroelectric-antiferroelectric multilayers that take into account the long range dipolar interactions were simulated by a Monte-Carlo method. Simulations were carried out for a 1+1 bilayer and a 5+5 superlattice. Phase stabilities of components comprising the structures with an electrostatic-like coupling term were also studied. An electrostatic-like coupling, in the absence of an applied field, can drive the ferroelectric layers towards 180º domains with very flat domain interfaces mainly due to the competition between this term and the dipole-dipole interaction. The antiferroelectric layers do not undergo an antiferroelectric-to-ferroelectric transition under the influence of an electrostatic-like coupling between layers as the ferroelectric layer splits into periodic domains at the expense of the domain wall energy. The long-range interactions become significant near the interfaces. For high periodicity structures with several interfaces, the interlayer long-range interactions substantially impact the configuration of the ferroelectric layers while the antiferroelectric layers remain quite stable unless these layers are near the Neel temperature. In systems investigated with several interfaces, the hysteresis loops do not exhibit a clear presence of antiferroelectricity that could be expected in the presence of anti-parallel dipoles, i. e., the switching takes place abruptly. Some recent experimental observations in ferroelectric-antiferroelectric multilayers are discussed where we conclude that the different electrical properties of bilayers and superlattices are not only due to strain effects alone but also long-range interactions. The latter manifests itself particularly in superlattices where layers are periodically exposed to each other at the interfaces

Order-Revealing Encryption and the Hardness of Private Learning

An order-revealing encryption scheme gives a public procedure by which two ciphertexts can be compared to reveal the ordering of their underlying plaintexts. We show how to use order-revealing encryption to separate computationally efficient PAC learning from efficient $(\epsilon, \delta)$-differentially private PAC learning. That is, we construct a concept class that is efficiently PAC learnable, but for which every efficient learner fails to be differentially private. This answers a question of Kasiviswanathan et al. (FOCS '08, SIAM J. Comput. '11). To prove our result, we give a generic transformation from an order-revealing encryption scheme into one with strongly correct comparison, which enables the consistent comparison of ciphertexts that are not obtained as the valid encryption of any message. We believe this construction may be of independent interest.Comment: 28 page

The level of VEGF-A in the lacrimal fluid of diabetic retinopathy

The lacrimal fluid was investigated in 56 people (95 eyes) with type II diabetes, of which 11 (11 eyes) with no signs of diabetic retinopathy and 45 patients (84 eyes) suffering from diabetic retinopathy of varying severity. Investigation of VEGF-A (vascular endothelial growth factor A) in stimulated lacrimal fluid revealed its level in all patients. It was significantly higher in patients with diabetic retinopathy compared with data that have been obtained in patients with diabetes, but without signs of diabetic retinopathy. Statistically significant differences in the level of VEGF-A in patients with non-proliferative and proliferative retinopathy of 1-3 stages have not been identified. At the same time in patients with far-advanced retinopathy with marked variations of fatal retina and vitreous body (detachment expressed gliosis), but without evidence of neovascularization of the anterior eye, a significant decrease in the level of vasoproliferative factors has revealed

Security analysis of standard authentication and key agreement protocols utilising timestamps

We propose a generic modelling technique that can be used to extend existing frameworks for theoretical security analysis in order to capture the use of timestamps. We apply this technique to two of the most popular models adopted in literature (Bellare-Rogaway and Canetti-Krawczyk). We analyse previous results obtained using these models in light of the proposed extensions, and demonstrate their application to a new class of protocols. In the timed CK model we concentrate on modular design and analysis of protocols, and propose a more efficient timed authenticator relying on timestamps. The structure of this new authenticator implies that an authentication mechanism standardised in ISO-9798 is secure. Finally, we use our timed extension to the BR model to establish the security of an efficient ISO protocol for key transport and unilateral entity authentication

«Functional» HLA-DRB1 genotyping - the way of the prediction of risk of dm1 development

The new way of prediction of high and low risk of development DM1 which allows to estimate genetic risk of development DM1 without dependence from an ethnic origin by the use of "functional" HLA-DRB1 -genotype, that consist of 2 variants of DRB1 -gene, associated with development DM1. This method can serve as additional laboratory sign for autoimmune’s diabetes diagnosis establishment and also can be used for prediction of development DM1 among relatives of patients DM1 for the purpose of revealing of persons with high and low genetic predisposition to development DM1.Описан новый способ прогнозирования высокого и низкого риска развития СД1, который позволяет оценивать генетический риск развития СД1 вне зависимости от этнической принадлежности обследуемого на основе установления «функционального» HLA-DRB1-генотипа, состоящего из 2 вариантов гена DRB1, ассоциированных с развитием СД1. Метод может служить дополнительным лабораторным симптомом СД1 для дифференциальной диагностики аутоиммунного сахарного диабета, а также может быть использован для прогнозирования развития СД1 у родственников больных СД1 с целью выявления лиц с высокой и низкой генетической предрасположенностью к развитию СД1

Crystallographic Education in the 21st Century

There are many methods that can be used to incorporate concepts of crystallography into the learning experiences of students, whether they are in elementary school, at university or part of the public at large. It is not always critical that those who teach crystallography have immediate access to diffraction equipment to be able to introduce the concepts of symmetry, packing or molecular structure in an age- and audience-appropriate manner. Crystallography can be used as a tool for teaching general chemistry concepts as well as general research techniques without ever having a student determine a crystal structure. Thus, methods for younger students to perform crystal growth experiments of simple inorganic salts, organic compounds and even metals are presented. For settings where crystallographic instrumentation is accessible (proximally or remotely), students can be involved in all steps of the process, from crystal growth, to data collection, through structure solution and refinement, to final publication. Several approaches based on the presentations in the MS92 Microsymposium at the IUCr 23rd Congress and General Assembly are reported. The topics cover methods for introducing crystallography to undergraduate students as part of a core chemistry curriculum; a successful short-course workshop intended to bootstrap researchers who rely on crystallography for their work; and efforts to bring crystallography to secondary school children and non-science majors. In addition to these workshops, demonstrations and long-format courses, open-format crystallographic databases and three-dimensional printed models as tools that can be used to excite target audiences and inspire them to pursue a deeper understanding of crystallography are described