Multiple Masking Research Articles

Multiplicative Masking for AES in Hardware

Hardware masked AES designs usually rely on Boolean masking and perform the computation of the S-box using the tower-field decomposition. On the other hand, splitting sensitive variables in a multiplicative way is more amenable for the computation of the AES S-box, as noted by Akkar and Giraud. However, multiplicative masking needs to be implemented carefully not to be vulnerable to first-order DPA with a zero-value power model. Up to now, sound higher-order multiplicative masking schemes have been implemented only in software. In this work, we demonstrate the first hardware implementation of AES using multiplicative masks. The method is tailored to be secure even if the underlying gates are not ideal and glitches occur in the circuit. We detail the design process of first- and second-order secure AES-128 cores, which result in the smallest die area to date among previous state-of-the-art masked AES implementations with comparable randomness cost and latency. The first- and second-order masked implementations improve resp. 29% and 18% over these designs. We deploy our construction on a Spartan-6 FPGA and perform a side-channel evaluation. No leakage is detected with up to 50 million traces for both our first- and second-order implementation. For the latter, this holds both for univariate and bivariate analysis.

Mixing Additive and Multiplicative Masking for Probing Secure Polynomial Evaluation Methods

Masking is a sound countermeasure to protect implementations of block- cipher algorithms against Side Channel Analysis (SCA). Currently, the most efficient masking schemes use Lagrange’s Interpolation Theorem in order to represent any S- box by a polynomial function over a binary finite field. Masking the processing of an S-box is then achieved by masking every operation involved in the evaluation of its polynomial representation. While the common approach requires to use the well- known Ishai-Sahai-Wagner (ISW) scheme in order to secure this processing, there exist alternatives. In the particular case of power functions, Genelle, Prouff and Quisquater proposed an efficient masking scheme (GPQ). However, no generalization has been suggested for polynomial functions so far. In this paper, we solve the open problem of extending GPQ for polynomials, and we also solve the open problem of proving that both the original scheme and its variants for polynomials satisfy the t-SNI security definition. Our approach to extend GPQ is based on the cyclotomic method and results in an alternate cyclotomic method which is three times faster in practice than the original proposal in almost all scenarios we address. The best- known method for polynomial evaluation is currently CRV which requires to use the cyclotomic method for one of its step. We also show how to plug our alternate cyclo- tomic approach into CRV and again provide an alternate approach that outperforms the original in almost all scenarios. We consider the masking of n-bit S-boxes for n ∈ [4;8] and we get in practice 35% improvement of efficiency for S-boxes with dimension n ∈ {5,7,8} and 25% for 6-bit S-boxes.

Collusion Resistant Multi-Matrix Masking for Privacy-Preserving Data Collection.

An integral part of any social or medical research is the availability of reliable data. For the integrity of participants' responses, a secure environment for collecting sensitive data is required. This paper introduces a novel privacy-preserving data collection method: collusion resistant multi-matrix masking (CRM3). The CRM3 method requires multiple masking service providers (MSP), each generating its own random masking matrices. The key step is that each participant's data is randomly decomposed into the sum of component vectors, and each component vector is sent to the MSPs for masking in a different order. The CRM3 method publicly releases two sets of masked data: one being right multiplied by random invertible matrices and the other being left multiplied by random orthogonal matrices. Both MSPs and the released data may be hosted on cloud platforms. Our data collection and release procedure is designed so that MSPs and the data collector are not able to derive the original participants' data hence providing strong privacy protection. However, statistical inference on parameters of interest will produce exactly the same results from the masked data as from the original data, under commonly used statistical methods such as general linear model, contingency table analysis, logistic regression, and Cox proportional hazard regression.

Time-dependent tomographic reconstruction of the solar corona

Solar rotational tomography (SRT) applied to white-light coronal images observed at multiple aspect angles has been the preferred approach for determining the three-dimensional (3D) electron density structure of the solar corona. However, it is seriously hampered by the restrictive assumption that the corona is time-invariant which introduces significant errors in the reconstruction. We first explore several methods to mitigate the temporal variation of the corona by decoupling the "fast-varying" inner corona from the "slow-moving" outer corona using multiple masking (either by juxtaposition or recursive combination) and radial weighting. Weighting with a radial exponential profile provides some improvement over a classical reconstruction but only beyond 3 Rsun. We next consider a full time-dependent tomographic reconstruction involving spatio-temporal regularization and further introduce a co-rotating regularization aimed at preventing concentration of reconstructed density in the plane of the sky. Crucial to testing our procedure and properly tuning the regularization parameters is the introduction of a time-dependent MHD model of the corona based on observed magnetograms to build a time-series of synthetic images of the corona. Our procedure, which successfully reproduces the time-varying model corona, is finally applied to a set of of 53 LASCO-C2 pB images roughly evenly spaced in time from 15 to 29 March 2009. Our procedure paves the way to a time-dependent tomographic reconstruction of the coronal electron density to the whole set of LASCO-C2 images presently spanning 20 years.

Zoning as a Human Rights Violation: Is Zoning Associated with Increased Health-Risk and Health Care Disparity?

Human rights violations are not always as clear as people would like. When they involve the direct violation of an individual’s life, such as forced labor or false imprisonment, or they result in death, society can easily identify and oppose them. On the other hand less conspicuous risks derived from governmental policies such as zoning laws are difficult to recognize. This review provides evidence of how zoning is associated with health-risk and disparity in health care delivery. Disparities resulting from zoning heighten human stress and lead to maladapted behavioral changes that cluster with diseased conditions like obesity. Zoning, as a human rights violation is difficult to understand, however, this lack of recognition is a direct result from socially acceptable processes that have created the way we live our life. There are multiple social processes masking human rights violations resulting from the construction of our built environment. Without a close examination of these processes it can appear that those violated are the victims of chance or bad choices, but in fact, it is socially constructed circumstances that lead these people to be violated. The depth of the human rights violations runs much deeper than just the individual. These human rights violations penetrate and become pervasive all the way to the unborn next generation. The subsequent impacts from the infringement of a person's rights linger when violations inform the circumstances that determine the type of education and employment available to a person. The aim of this paper will be to outline the process of how the built environment leads to human rights violations. Processes begin with the act of creating the zoning laws; zoning has the unintentional and intentional act of creating segregation, further, it is segregation that leads to discrimination, and the impact of discrimination has very real and lasting adverse health outcomes. The presence of disparities created by socially constructed processes such as zoning results in stress and the increase in adverse health outcomes such as obesity, one of the major forerunners of the current global epidemic of non-communicable diseases.

EMDBAM: A Low-Power Dual Bit Associative Memory With Match Error and Mask Control

A ternary content addressable memory (TCAM) speeds up the search process in the memory by searching through prestored contents rather than addresses. The additional don't care (X) state makes the TCAM suitable for many network applications but the large amount of cell requirement for storage consumes high power and takes a large design area. This paper presents a novel architecture of TCAM, which prestores 2 bits of data in an up-down manner and provides multiple masking operations through a single control multimasking circuit. The proposed dual bit associative memory with match error and mask control (EMDBAM) consumes low power and selects the valid value on matchline through match error controller. The proposed design has been implemented using a standard 45-nm CMOS technology, and the extracted layout has been simulated using SPECTRE with the supply voltage at 1 V. The proposed EMDBAM can reduce the cell area by 39% compared with a basic TCAM design with a reduction of 9.6% in the energy-delay product.

Mitogenomics does not resolve deep molluscan relationships (yet?)

The origin of molluscs among lophotrochozoan metazoans is unresolved and interclass relationships are contradictory between morphology-based, multi-locus, and recent phylogenomic analyses. Within the “Deep Metazoan Phylogeny” framework, all available molluscan mitochondrial genomes were compiled, covering 6 of 8 classes. Genomes were reannotated, and 13 protein coding genes (PCGs) were analyzed in various taxon settings, under multiple masking and coding regimes. Maximum Likelihood based methods were used for phylogenetic reconstructions. In all cases, molluscs result mixed up with lophotrochozoan outgroups, and most molluscan classes with more than single representatives available are non-monophyletic. We discuss systematic errors such as long branch attraction to cause aberrant, basal positions of fast evolving ingroups such as scaphopods, patellogastropods and, in particular, the gastropod subgroup Heterobranchia. Mitochondrial sequences analyzed either as amino acids or nucleotides may perform well in some (Cephalopoda) but not in other palaeozoic molluscan groups; they are not suitable to reconstruct deep (Cambrian) molluscan evolution.Supposedly “rare” mitochondrial genome level features have long been promoted as phylogenetically informative. In our newly annotated data set, features such as genome size, transcription on one or both strands, and certain coupled pairs of PCGs show a homoplastic, but obviously non-random distribution. Apparently congruent (but not unambiguous) signal for non-trivial subclades, e.g. for a clade composed of pteriomorph and heterodont bivalves, needs confirmation from a more comprehensive bivalve sampling. We found that larger clusters not only of PCGs but also of rRNAs and even tRNAs can bear local phylogenetic signal; adding trnG–trnE to the end of the ancestral cluster trnM–trnC–trnY–trnW–trnQ might be synapomorphic for Mollusca. Mitochondrial gene arrangement and other genome level features explored and reviewed herein thus failed as golden bullets, but are promising as additional characters or evidence supporting deep molluscan clades revealed by other data sets. A representative and dense sampling of molluscan subgroups may contribute to resolve contentious interclass relationships in the future, and is vital for exploring the evolution of especially diverse mitochondrial genomes in molluscs.

Monte Carlo Simulation of Multiple Masking Processes for Anisotropic Wet Etching

The Monte Carlo (MC) method is explored to simulate the composed silicon fabrication processes of anisotropic wet etching.The multi-step etching processes with multiple masking capabilities are implemented in the simulation program.The removal probability function is applied to calculating the parameters of removal probabilities in the MC calculation.This approach can simulate the effects of silicon oxide and silicon nitride layers in wet anisotropic etching and the transformation of the multi-mask patterns.The simulation of the six steps processes for atomic force microscope (AFM) probe array is carried out to verify this MC method.

The effects of hearing loss and age on the benefit of spatial separation between multiple talkers in reverberant rooms

This study investigated the interaction between hearing loss, reverberation, and age on the benefit of spatially separating multiple masking talkers from a target talker. Four listener groups were tested based on hearing status and age. On every trial listeners heard three different sentences spoken simultaneously by different female talkers. Listeners reported keywords from the target sentence, which was presented at a fixed and known location. Maskers were colocated with the target or presented from spatially separated and symmetrically placed loudspeakers, creating a situation with no simple "better-ear." Reverberation was also varied. The target-to-masker ratio at threshold for identification of the fixed-level target was measured by adapting the level of the maskers. On average, listeners with hearing loss showed less spatial release from masking than normal-hearing listeners. Age was a significant factor although small differences in hearing sensitivity across age groups may have contributed to this effect. Spatial release was reduced in the more reverberant room condition but in most cases a significant advantage remained. These results provide evidence for a large benefit of spatial separation in a multitalker situation that is likely due to perceptual factors. However, this benefit is significantly reduced by both hearing loss and reverberation.

DEMETER HIGH RESOLUTION 3D SEISMIC SURVEY—REVITALISED DEVELOPMENT AND EXPLORATION ON THE NORTH WEST SHELF, AUSTRALIA

The newly acquired 3,590 km2 Demeter 3D high resolution seismic survey covers most of the North West Shelf Venture (NWSV) area; a prolific hydrocarbon province with ultimate recoverable reserves of greater than 30 Tcf gas and 1.5 billion bbls of oil and natural gas liquids. The exploration and development of this area has evolved in parallel with the advent of new technologies, maturing into the present phase of revitalised development and exploration based on the Demeter 3D.The NWSV is entering a period of growing gas market demand and infrastructure expansion, combined with a more diverse and mature supply portfolio of offshore fields. A sequence of satellite fields will require optimised development over the next 5–10 years, with a large number of wells to be drilled.The NWSV area is acknowledged to be a complex seismic environment that, until recently, was imaged by a patchwork of eight vintage (1981–98) 3D seismic surveys, each acquired with different parameters. With most of the clearly defined structural highs drilled, exploration success in recent years has been modest. This is due primarily to severe seismic multiple contamination masking the more subtle and deeper exploration prospects. The poor quality and low resolution of vintage seismic data has also impeded reservoir characterisation and sub-surface modelling. These sub-surface uncertainties, together with the large planned expenditure associated with forthcoming development, justified the need for the Demeter leading edge 3D seismic acquisition and processing techniques to underpin field development planning and reserves evaluations.The objective of the Demeter 3D survey was to re-image the NWSV area with a single acquisition and processing sequence to reduce multiple contamination and improve imaging of intra-reservoir architecture. Single source (133 nominal fold), shallow solid streamer acquisition combined with five stages of demultiple and detailed velocity analysis are considered key components of Demeter.The final Demeter volumes were delivered early 2005 and already some benefits of the higher resolution data have been realised, exemplified in the following:Successful drilling of development wells on the Wanaea, Lambert and Hermes oil fields and identification of further opportunities on Wanaea-Cossack and Lambert- Hermes;Dramatic improvements in seismic data quality observed at the giant Perseus gas field helping define seven development well locations;Considerably improved definition of fluvial channel architecture in the south of the Goodwyn gas field allowing for improved well placement and understanding of reservoir distribution;Identification of new exploration prospects and reevaluation of the existing prospect portfolio. Although the Demeter data set has given significant bandwidth needed for this revitalised phase of exploration and development, there remain areas that still suffer from poor seismic imaging, providing challenges for the future application of new technologies.

Detection of a target taste in a complex masker.

Detection thresholds for sodium chloride were compared in aqueous solution, in mixture with a sucrose masker, in mixture with a citric acid masker, and in mixture with both of these maskers together. Separately the two maskers raised the threshold of sodium chloride by three to four times, and together by over nine times, a result consistent with independence (additivity) of the two masking effects. To achieve comparable masking with either sucrose alone or with citric acid alone would require increasing their masking concentrations by about ten times. Hence multiple masking can be a far more efficient means of concealing a taste, whether an unpleasant one (e.g. the bitter taste of medicine) or a pleasant one (e.g. a salty or sweet condiment). Multiple masking has dietary and culinary significance, especially for middle aged and elderly persons concerned about salt intake, because their thresholds for NaCl, whether with or without maskers, are typically two or three times higher than those of youthful persons.

Two-dimensional implantation profile simulator — RETRO

A computer simulator RETRO is developed to visualize two-dimensional implantation profiles through arbitrary mask shapes. Simulation features of RETRO include: (1) arbitrary mask shape which can be described by multiple straight-line segments, (2) multiple masking layers, (3) multiple implants, and (4) dopant compensation. Graphical display of the 2D profile after input of user-specified mask shape only takes seconds of computer time on an IBM personal computer.

Masking Level Difference at Relatively High Masker Levels: Preliminary Report

The binaural masking level difference (MLD) was measured at multiple masking levels (i.e. 500 Hz narrow band noise presented at 50-100 dB overall SPL) in normal hearing subjects and clinical subjects with varying types and degrees of hearing loss. MLD versus noise level (MLD-NL) functions then were derived for each subject. Some growth in the MLD-NL was seen in nearly all cases of hearing loss up to 70 dB in the poorer ear. These findings suggest that the MLD-NL function may provide the basis for extending the diagnostic usefulness of the MLD test in cases of substantive hearing loss.

Fabrication and performance of GaAs MESFETs with graded channel doping using focused ion-beam implantation

The dopant concentration in the channel region of GaAs MESFETs is tailored by focused ion-beam implantation, allowing the fabrication of devices with higher power ratings than uniformly doped devices of similar dimensions. With this technique, multiple masking steps during fabrication and avoided, and dopant concentration can be changed with great precision in both position and magnitude. The effect of dopant grading on other device parameters, such as the transconductance and the pinch-off voltage, is reported. >

Multiple masking in a backward masking paradigm

A study was made of the effects of multiple visual masking upon variations in mask position, word frequency, and display on time. Ten subjects were shown five-letter words, four or five letters of which were immediately masked. These words, half of which were classified as frequent and the other half as infrequent, were displayed at different display on times. Results showed that (1) exposing a little information produces the same or better results than not exposing any, (2) variations in the position of the mask cause no increase in visual performance, and (3) in total masking one position shows no better results than any other. Findings indicated both word frequency and display on time are highly significant factors, whereas the masking position is not. Results warrant a parallel processing interpretation, rather than a serial one.

Solid-state micrologic elements

The design and structure of solid state micrologic elements is described. In discussing these elements, the emphasis is placed on the use of multiple diffusion, masking and evaporation in the fabrication of integrated microcircuits in a single piece of silicon. It is shown that both active and passive elements can be built into the silicon substrate and that electrical isolation of the individual components can be achieved when necessary. The techniques employed in making the interconnection will be described. Microphotographs and cross sectional views of these elements at various stages of construction are shown in conjunction with a discussion of the following process steps: 1. Materials preparation. 2. The seven masking operations. 3. Electrical isolation of active and passive elements within the silicon substrate. 4. Diffusion of active and passive elements. 5. Surface passivation. 6. Electrical interconnection of components. 7. Packaging and testing. Economy, reliability and design flexibility are some of the more important considerations of this approach. These are reviewed in connection with the present family of six micrologic elements. The feasibility of extending present technology to the development and manufacture of differing and more complex microcircuits and subsystems is discussed.