Concurrent error detection of fault-based side-channel cryptanalysis of 128-bit RC6 block cipher

Fault-based side channel cryptanalysis is very effective against symmetric and asymmetric encryption algorithms. Although straightforward hardware and time redundancy based concurrent error detection (CED) architectures can be used to thwart such attacks, they entail significant overhead (either area or performance). In this paper we investigate two systematic approaches to low-cost, low-latency CED for symmetric encryption algorithm RC6. The proposed techniques have been validated on FPGA implementations of RC6, one of the advanced encryption standard finalists.     

Viscous behaviour of glass-forming liquids: a thermodynamic approach

The temperature dependence of the viscosity of the undercooled melts exhibits an important role in the study of nucleation, crystal growth and the glass-forming ability of materials. Several attempts have been made to study the viscous behaviour of the glass-forming melts and these investigations are mainly based on free volume theory as well as on the configurational entropy model. In the present investigation, an attempt has been made to correlate the thermodynamic parameters with the viscosity of the glass-forming melts and to study the temperature dependence of the viscosity of undercooled liquids on the basis of the free volume theory as well as on the basis of the configurational entropy model of Adam and Gibbs. The entire study is confined on the expression for thermodynamic parameters reported by the authors recently. The expression obtained has been successfully applied to study the temperature dependence of the viscosity of the metallic, molecular and oxide glass-forming liquids.     

Efficient algorithms for selection of recovery points in tree taskmodels

Efficient solutions to the problem of optimally selecting recovery points are developed. The solutions are intended for models of computation in which task precedence has a tree structure and a task may fail due to the presence of faults. An algorithm to minimize the expected computation time of the task system under a uniprocessor environment has been developed for the binary tree model. The algorithm has time complexity of O(N₂), where N is the number of tasks, while previously reported procedures have exponential time requirements. The results are generalized for an arbitrary tree model     

High-breakdown-voltage AlInAs/GaInAs junction-modulated HEMT's(JHEMT's) with regrown ohmic contacts by MOCVD

A technology for increasing both the two-terminal gate-drain breakdown and subsequently the three-terminal-off-state breakdown of AlInAs/GaInAs high-electron-mobility transistors (HEMTs) to record values without substantial impact on other parameters is presented. The breakdown in these structures is dependent on the multiplication of electrons injected from the source (channel current) and the gate (gate leakage) into the channel. In addition, holes are generated by high fields at the drain and are injected back into the gate and source electrodes. These phenomena can be suppressed by increasing the gate barrier height and alleviating the fields at the drain. Both have been achieved by incorporating a p⁺-2DEG junction as the gate that modulates the 2DEG gas and by utilizing selective regrowth of the source and drain regions by MOCVD. The 1-μm-gate-length devices fabricated have two-terminal gate-drain and three-terminal-off-state breakdown voltages of 31 V and 28 V, respectively     

Loss of precious metal from Pt-Rh alloy under refractory oxide environments

Loss of precious metals from a Pt-10 wt% Rh alloy was studied at 1300° C in refractory oxides and fused quartz environments. After 60 and 150 h annealings, samples exposed to gaseous environments showed significant weight loss. The surface was attacked and characterized by micron-sized pits, as well as river-like striations. The pits were found to be enriched with silicon and/or aluminium depending upon the heating environment. Laser Raman microprobe identified that the major compound formed in the pits is -cristobalite.Direct solid state contact of Pt-Rh with Al₂O₃ and SiO₂ showed interactions between materials. The interaction was more extensive between Pt-Rh with SiO₂ than with Al₂O₃. On the other hand, no evidence of interaction except pitting and striation was observed on Pt-Rh when exposed to a vapour environment.The presence of pits and striation patterns indicated that refractory oxides attacked Pt-Rh under atmospheric conditions, and gave rise to the weight loss. Calculation of weight loss by an oxidation mechanism shows one to two orders of magnitude lower value than the actual weight loss. A new loss mechanism is proposed and discussed in this article.     

Chemical composition and bond structure of carbon-nitride films deposited by CH4/N2 dielectric barrier discharge

Carbon nitride films have been deposited by dielectric barrier discharge with a CH₄/N₂ gas mixture at different conditions. Fourier Transform Infrared (FTIR) spectroscopy, X-ray photo electron spectroscopy (XPS), Raman spectroscopy, Atomic force microscopy (AFM) and ellipsometry were used to systematically study chemical composition, bond structure and surface morphology of deposited films. Various bonds between carbon, nitrogen, hydrogen, and also oxygen were observed.     

A study of the cu clusters using gray-coded genetic algorithms and differential evolution

Energy minimization studies were carried out for a number of Cu clusters using binary and Gray-coded genetic algorithms along with real coded differential evolution, and their optimized ground state geometries are presented. The potential energy function is constructed using a two-body interaction methodology, involving both attractive and repulsive pair-potential terms. The results obtained through the evolutionary algorithms are compared against those obtained earlier using a Monte Carlo technique.     

Bulk free radical polymerizations of methyl methacrylateunder non-isothermal conditions and with intermediate additionof initiator: Experiments and modeling

Experimental data on the monomer conversion, x_m, and the weight average molecular weight, M_w, have been generated under several isothermal and non-isothermal conditions for the polymerization of methyl methacrylate in a rheometer-reactor assembly. The non-isothermal results, in particular, can be used to provide more stringent tests of kinetic models than isothermal data alone. A simple empirical model has been used to describe this system that accounts for the gel (Trommsdorff) and glass effects. The model involves only x_m and the temperature, and is quite general. The model parameters are tuned using only three sets of isothermal data. Good agreement is found between the experimental results and model predictions for a whole variety of experimental conditions, including non-isothermal operation and with intermediate addition of initiator. Because of its generality, this model is quite suitable for use for on-line optimizing control as well as for describing industrial reactors.     

Ozone Contactor Hydrodynamics

Tracer tests were conducted at the 6,000 pounds of ozone per day Tucson, CAP Water Treatment Plant in Tucson, Arizona. The tests were designed to determine T₁₀ values through the contactors at various operating conditions. The tests were modeled using three techniques. Peclet Number was calculated for each of the runs, which would indicate the hydrodynamic conditions inside the ozone contactor. The results indicated that the increase in water flow rate and the number of cells with gas flow increased Peclet Number. The flow rate of liquid seemed to impact the Peclet Number more than gas flow. The headloss in each cell appeared to be important in controlling the distribution of liquid and gas through the cell. A correlation was developed between the product of gas and liquid phase Reynolds Number and Peclet Number.