228 research outputs found

    SPHINCS+^+ post-quantum digital signature scheme with Streebog hash function

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    Many commonly used public key cryptosystems will become insecure once a scalable quantum computer is built. New cryptographic schemes that can guarantee protection against attacks with quantum computers, so-called post-quantum algorithms, have emerged in recent decades. One of the most promising candidates for a post-quantum signature scheme is SPHINCS+^+, which is based on cryptographic hash functions. In this contribution, we analyze the use of the new Russian standardized hash function, known as Streebog, for the implementation of the SPHINCS+^+ signature scheme. We provide a performance comparison with SHA-256-based instantiation and give benchmarks for various sets of parameters.Comment: 5 pages, 2 figures, 3 table

    Lining Design for Alborz Tunnel in Iran

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    The paper describes the application of analytical methods if tunnel linings design under static, tectonic and seismic effects for the design of the transport tunnel Albors in Iran. The methods are based on solutions of the corresponding plane problems of the elasticity theory simulating the initial stress fields in the rock mass caused by gravitational or tectonic forces and actions of long arbitrary directed longitudinal (P) and shear (S) waves propagating in the plane of the tunnel cross-section. For the design of tunnel linings under seismic effects the original approach has been applied consisting in the determination of maximal compressive and tensile circumferential stresses wich may appear in points of the lining internal outline at any combinations and directions of P- and S- waves

    Strong alkalinization of Chara cell surface in the area of cell wall incision as an early event in mechanoperception

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    AbstractMechanical wounding of cell walls occurring in plants under the impact of pathogens or herbivores can be mimicked by cell wall incision with a glass micropipette. Measurements of pH at the surface of Chara corallina internodes following microperforation of cell wall revealed a rapid (10–30s) localized alkalinization of the apoplast after a lag period of 10–20s. The pH increase induced by incision could be as large as 3 pH units and relaxed slowly, with a halftime up to 20min. The axial pH profile around the incision zone was bell-shaped and localized to a small area, extending over a distance of about 100μm. The pH response was suppressed by lowering cell turgor upon the replacement of artificial pond water (APW) with APW containing 50mM sorbitol. Stretching of the plasma membrane during its impression into the cell wall defect is likely to activate the Ca2+ channels, as evidenced from sensitivity of the incision-induced alkalinization to the external calcium concentration and to the addition of Ca2+-channel blockers, such as La3+, Gd3+, and Zn2+. The maximal pH values attained at the incision site (~10.0) were close to pH in light-dependent alkaline zones of Chara cells. The involvement of cytoskeleton in the origin of alkaline patch was documented by observations that the incision-induced pH transients were suppressed by the inhibitors of microtubules (oryzalin and taxol) and, to a lesser extent, by the actin inhibitor (cytochalasin B). The results indicate that the localized increase in apoplastic pH is an early event in mechanoperception and depends on light, cytoskeleton, and intracellular calcium

    Volga-Ural Sandy Plague Focus Differentiation against Epizootic Manifestations by Means of Circular Extrapolation

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    Displayed are the results of study of the Volga-Ural sandy plague focus spatial structure. Constructed has been the map of the area with long-lasting persistent epizootic manifestations, monitored throughout the whole period from 1926 to 2012, using method of circular extrapolation of plague microbe detection points. Epizootic area mapping and map adjustment have been carried out automatically with the help of ArcGIS-10 software. The map displays the dislocation of plague focus activity nuclei and zones of short-term epizootic process registration; identified have been their quantitative parameters. Cartographic model of plague-focal territory differentiation against epizootic manifestation index is designed for validated planning of epidemiological surveillance activities and further studies of plague enzootics issues. The data obtained can be used for epidemiological zoning of territories as regards plague

    Global Guidance for Local Generalization in Model Checking

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    SMT-based model checkers, especially IC3-style ones, are currently the most effective techniques for verification of infinite state systems. They infer global inductive invariants via local reasoning about a single step of the transition relation of a system, while employing SMT-based procedures, such as interpolation, to mitigate the limitations of local reasoning and allow for better generalization. Unfortunately, these mitigations intertwine model checking with heuristics of the underlying SMT-solver, negatively affecting stability of model checking. In this paper, we propose to tackle the limitations of locality in a systematic manner. We introduce explicit global guidance into the local reasoning performed by IC3-style algorithms. To this end, we extend the SMT-IC3 paradigm with three novel rules, designed to mitigate fundamental sources of failure that stem from locality. We instantiate these rules for the theory of Linear Integer Arithmetic and implement them on top of SPACER solver in Z3. Our empirical results show that GSPACER, SPACER extended with global guidance, is significantly more effective than both SPACER and sole global reasoning, and, furthermore, is insensitive to interpolation.Comment: Published in CAV 202

    Mightyl: A compositional translation from mitl to timed automata

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    Metric Interval Temporal Logic (MITL) was first proposed in the early 1990s as a specification formalism for real-time systems. Apart from its appealing intuitive syntax, there are also theoretical evidences that make MITL a prime real-time counterpart of Linear Temporal Logic (LTL). Unfortunately, the tool support for MITL verification is still lacking to this day. In this paper, we propose a new construction from MITL to timed automata via very-weak one-clock alternating timed automata. Our construction subsumes the well-known construction from LTL to BĂĽchi automata by Gastin and Oddoux and yet has the additional benefits of being compositional and integrating easily with existing tools. We implement the construction in our new tool MightyL and report on experiments using Uppaal and LTSmin as back-ends

    Global Guidance for Local Generalization in Model Checking

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    SMT-based model checkers, especially IC3-style ones, are currently the most effective techniques for verification of infinite state systems. They infer global inductive invariants via local reasoning about a single step of the transition relation of a system, while employing SMT-based procedures, such as interpolation, to mitigate the limitations of local reasoning and allow for better generalization. Unfortunately, these mitigations intertwine model checking with heuristics of the underlying SMT-solver, negatively affecting stability of model checking. In this paper, we propose to tackle the limitations of locality in a systematic manner. We introduce explicit global guidance into the local reasoning performed by IC3-style algorithms. To this end, we extend the SMT-IC3 paradigm with three novel rules, designed to mitigate fundamental sources of failure that stem from locality. We instantiate these rules for the theory of Linear Integer Arithmetic and implement them on top of Spacer solver in Z3. Our empirical results show that GSpacer, Spacer extended with global guidance, is significantly more effective than both Spacer and sole global reasoning, and, furthermore, is insensitive to interpolation

    Monkeypox Virus Dissemination in Case of Intranasal Infection of Mice

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    By the experiments of in vivo intranasal infection of 8-10-days-old outbread ICR mice with Monkeypox virus (MPV) in a dose equal 3.83 lg FFU/specimen, investigated was dynamics of the virus accumulation within various organs, blood cells, and blood serum. In 2 days after infection MPV was detected in blood cells, nasal cavity, lungs, spleen, and duodenum, and in 5 days after - in brain, trachea, liver, kidneys, and blood serum. It was established that 7 days after infection the highest level of MPV production was in the lungs, nasal cavity, and brain, where virus titers in 5 % homogenates were (5.7±0.1), (5.5±0.1), and (5.3±0.3) lg FFU/ml, respectively. In the blood cells virus was traced in 2, 5, and 7 days after challenge, while in blood serum - in 5 and 7 days. MPV blood transfer to the secondary target organs (liver, spleen, duodenum, kidneys, et al. ) was operational, probably, due to the virus proliferation in blood corpuscles. The data obtained and the worked out scheme of MPV dissemination in an organism can be used for the selection and construction of therapeutic anti-pox virus preparations with precise targeted drug delivery

    Sensitivity of Different Animal Species to Monkeypox Virus

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    Studied is the sensitivity of different animal species (white mice, rabbits, mini-pigs, and marmots) to Monkeypox virus (MPXV). Determined is the fact that MPXV-sensitive are groundhogs (ID50 and LD50 5 lg of PFU in case of intranasal inoculation). The most pronounced clinical signs of the disease such as varioliform eruption all over body and mucous linings, purulent discharges out of nasal cavity, lymphadenitis, loss of coordination, tremor of extremities, fever, hyper-aggressiveness, disheveled hair have been registered in groundhogs. The highest viral loads in the majority of fallen marmots have been observed in nasal mucosa, trachea, lungs, and pock-marked skin (>6,0 lg PFU/g). The symptomatology of the disease in mice as compared to groundhogs is a bit milder: purulent conjunctivitis, blepharitis, and disheveled hair. As for mini-pigs and rabbits, no visual signs of the disease have been observed in them
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