Multivariate High-Order Attacks of Shuffled Tables Recomputation

Masking schemes based on tables recomputation are classical countermeasures against high-order side-channel attacks. Still, they are known to be attackable at order d in the case the masking involves d shares. In this work, we mathematically show that an attack of order strictly greater than d can be more successful than an attack at order d. To do so, we leverage the idea presented by Tunstall, Whitnall and Oswald at FSE 2013: We exhibit attacks which exploit the multiple leakages linked to one mask during the recomputation of tables. Specifically, regarding first-order table recomputation, improved by a shuffled execution, we show that there is a window of opportunity, in terms of noise variance, where a novel highly multivariate third-order attack is more efficient than a classical bivariate second-order attack. Moreover, we show on the example of the high-order secure table computation presented by Coron at EUROCRYPT 2014 that the window of opportunity enlarges linearly with the security order d. These results extend that of the CHES ’15 eponymous paper. Here, we also investigate the case of degree one leakage models and formally show that the Hamming weight model is the less favorable to the attacker. Eventually, we validate our attack on a real ATMEL smartcard.     

Liver is not essential for solute transport during peritoneal dialysis

Based on theoretical calculations on solute exchange capacities of various peritoneal tissues, the liver has been predicted to account for up to 43% of the permeability-surface area product (PS) of the entire peritoneal "membrane" for a small solute (sucrose) during peritoneal dialysis (PD). In these calculations, the abdominal wall and the diaphragm were found to contribute only approximately 10 to 15% of the total PS. However, evisceration has in previous studies been shown to affect the PS characteristics during PD only marginally (10 to 30%). In such evisceration experiments the liver was usually not removed, and therefore it has been suggested that an intact liver might have significantly contributed to the solute exchange under these premises. We assessed the peritoneal PS of 51Cr-EDTA (constantly infused intravenously) and the plasma-to-peritoneal clearance (ClB-->P) of 125I-human serum albumin (RISA) (given as an i.v. bolus) in Wistar rats during acute PD. In one group of rats the liver surface was sealed off using Histoacrylate glue (N = 6) and in another group a 90% hepatectomy was performed, the remaining portion of the liver, usually the right lower lobe, being sealed off by glue (N = 6). A third group was sham operated to serve as control (N = 12). The PS for 51Cr-EDTA was 0.32 +/- 0.03(+/- SE) ml. min-1 (N = 12) during control, 0.32 +/- 0.04 ml.min-1 after "sealing" of the liver surface (N = 6, P > 0.1) and 0.40 +/- 0.03 after hepatectomy (N = 6, P > 0.1), that is, remained unchanged after experimental intervention. The CIB-->P of RISA during control was 5.88 +/- 1.0 microliter.min-1 (N = 10), and was not altered after hepatectomy, 6.17 +/- 0.48 microliters.min-1 (N = 5, P > 0.1), but slightly increased after liver surface sealing (9.69 +/- 1.09 microliters.min-1, N = 5, P < 0.05). In conclusion, the present experiments indicate that the liver does not play an essential role in the overall solute exchange between the plasma and the peritoneal cavity (PC) during PD.     

Integrating SLAM and gas distribution mapping (SLAM-GDM) for real-time gas source localization

Gas distribution mapping (GDM) learns models of the spatial distribution of gas concentrations across 2D/3D environments, among others, for the purpose of localizing gas sources. GDM requires run-time robot positioning in order to associate measurements with locations in a global coordinate frame. Most approaches assume that the robot has perfect knowledge about its position, which does not necessarily hold in realistic scenarios. We argue that the simultaneous localization and mapping (SLAM) algorithm should be used together with GDM to allow operation in an unknown environment. This paper proposes an SLAM-GDM approach that combines Hector SLAM and Kernel DM?+?V through a map merging technique. We argue that Hector SLAM is suitable for the SLAM-GDM approach since it does not perform loop closure or global corrections, which in turn would require to re-compute the gas distribution map. Real-time experiments were conducted in an environment with single and multiple gas sources. The results showed that the predictions of gas source location in all trials were often correct to around 0.5–1.5 m for the large indoor area being tested. The results also verified that the proposed SLAM-GDM approach and the designed system were able to achieve real-time operation.     

Low‐Energy Room‐Temperature Healing of Cellular Metals

Healing metallic materials involves high temperatures and large energy inputs. This work demonstrates rapid, effective, low‐energy, and room‐temperature healing of metallic materials by using electrochemistry and polymer‐coated cellular nickel to mimic the transport‐mediated healing of bone. The polymer coating enables selective healing only at the fracture site, electrochemical reactions transport metal ions from a metal source to fractured areas, and the cellular structure of the metal allows facile ion transport to healing sites and effective recovery of strength and toughness when the cellular metal is subjected to three types of damage (scission fracture, tensile failure, and plastic deformation). Using this strategy, samples fractured in tension and by scission recover 100% of their tensile strength in as little as 10 and 4 h of healing. The healing process is stochastic, thus a statistical method is used to quantify and predict the likelihood of achieving target healing strengths based on energy input. This electrochemistry‐based approach enables the first demonstration of room‐temperature healing of structural metallic materials and requires several orders of magnitude less energy than many previously reported metal healing techniques.     

Synthetically engineered microbes reveal interesting principles of cooperation

Cooperation is ubiquitous in biological systems. However, if natural selection favors traits that confer an advantage to one individual over another, then helping others would be paradoxical. Nevertheless, cooperation persists and is critical in maintaining homeostasis in systems ranging from populations of bacteria to groupings of mammals. Developing an understanding of the dynamics and mechanisms by which cooperation operates is critical in understanding ecological and evolutionary relationships. Over the past decade, synthetic biology has emerged as a powerful tool to study social dynamics. By engineering rationally controlled and modulatable behavior into microbes, we have increased our overall understanding of how cooperation enhances, or conversely constrains, populations. Furthermore, it has increased our understanding of how cooperation is maintained within populations, which may provide a useful framework to influence populations by altering cooperation. As many bacterial pathogens require cooperation to infect the host and survive, the principles developed using synthetic biology offer promise of developing novel tools and strategies to treat infections, which may reduce the use of antimicrobial agents. Overall, the use of engineered cooperative microbes has allowed the field to verify existing, and develop novel, theories that may govern cooperative behaviors at all levels of biology.

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Engineered disulfide bonds in recombinant human interferon-{gamma}: the impact of the N-terminal helix A and the AB-loop on protein stability

Insertion sites for cysteines with optimal stereochemistry forthe formation of unstrained disulfide bridges were identifiedin recombinant human interferon- (rhu-IFN-) by computer modelling.We have engineered two different disulfide cross-linked mutants,containing a pair of symmetry-related disulfide bonds, whichstabilize the N-termini of both monomers of the homodimenc protein.Mutations E7C and S69C allow the formation of an intramonomerdisuffide bond between helices A and D. In contrast, the A17Cand H111C mutations lead to a covalent cross-link between bothmonomers. The AB-loop is linked to helix F. The fluorescenceproperties of native and disulfide cross-linked proteins werestudied as a function of guanidine hydrochloride concentration.Melting temperatures (T_m) were calculated from the decreasein CD ellipticity at 220 nm. The induction of the antiviraleffect was measured using A549 fibroblast cells infected withencephalomyocarditis virus. The ability to induce the expressionof the HLA-DR antigen in Colo 205 cells was determined by fluorescence-activatedcell scanning analysis. The stability of both mutants was stronglyenhanced against temperature- and cosolvent-induced unfolding.The T_m of mutant IFN- E7C/S69C was 15°C. All measured biologicalactivities of this mutant were equal to wild type. In the caseof the other mutant IFN- A17C/H111C, the T_m value was 25°C.This mutation abolishes nearly the entire biological activity(<1%) with no detectable changes of secondary structure inthe CD spectrum. Our results illustrate the importance of theN-terminal helix A and the AB-loop for the unfolding pathwayand thermodynamic stability of rhu-IFN-.     

Cottonseed,protein and oil yields and oil properties as affected by nitrogen and phosphorus fertilization and growth regulators

Two experiments were carried out at our research center during the 1981 and 1982 seasons on cotton cultivar Giza 75 (Gossypium barbadense L.) to investigate the influence of nitrogen fertilization rates (72, 144 or 216 kg/ha.), phosphorus levels (36 or 72 kg P₂O₅/ha.) and three growth regulators (IAA, IBA or NAA) applied to cotton plants at 10 ppm and sprayed three times (70, 85 and 100 days after sowing) on protein and oil yields, and oil properties. A randomized complete block design with four replications treatment combinations was used. The combined analysis of the results of the two seasons revealed that yields of cottonseed, oil and protein increased by raising nitrogen and phosphorus levels and under the application of growth regulators. Seed index increased by raising the added nitrogen and the applied growth regulants. No detectable effect of phosphorus levels was observed. The seed oil percentage decreased, although the protein percentage increased, when the nitrogen application rate was raised. Application of growth regulators and a high phosphorus level increased the seed oil percentage, but the seed protein percentage was not affected. The seed oil properties, i.e., acidity, saponification and iodine values, tended to decrease slightly by increasing the nitrogen application rate and the application of growth substances, but the trend reversed when the phosphorus level was raised. The mean values of oil specific gravity and refractive index did not show any definite responses.     

GGBFS as potential filler in polyester grout: Flexural strength and toughness

The effectiveness of ground granulated blast furnace slag (GGBFS) as filler in polyester resin grout was investigated. The mix proportions of polymer grout was properly designed and manufactured. The binder, hardener and fillers used in this study were isophatalic unsaturated polyester resin (IUPR), methyl ethyl ketone peroxide (MEKP) and river sand as well as GGBFS respectively. The amount of GGBFS incorporated was varied from 10% to 30% of total filler by weight. The performance of the grout was investigated in terms of flexural strength development and durability. Modulus of elasticity test was also conducted in order to study the effect of GGBFS on toughness of the grout. Results were compared with the control grout without the slag as filler. The results showed that the use of GGBFS as filler has improved the performance of polyester resin grout. The grout has proven itself durable against the hostile environment of Malaysia and its performance were similar to that of epoxy resins but very much cheaper than the epoxy resin readily available in the market.