720 research outputs found
Hardware Accelerators for Elliptic Curve Cryptography
No full textPuttmann C, Shokrollahi J, Porrmann M, Rückert U. Hardware Accelerators for Elliptic Curve Cryptography. Advances in Radio Science. 2008;6:259-264.In this paper we explore different hardware accelerators
for cryptography based on elliptic curves. Furthermore,
we present a hierarchical multiprocessor system-onchip
(MPSoC) platform that can be used for fast integration
and evaluation of novel hardware accelerators. In respect
of two application scenarios the hardware accelerators are
coupled at different hierarchy levels of the MPSoC platform.
The whole system is implemented in a state of the art 65 nm
standard cell technology. Moreover, an FPGA-based rapid
prototyping system for fast system verification is presented.
Finally, a metric to analyze the resource efficiency by means
of chip area, execution time and energy consumption is introduced
Protection and Retrieval of Encrypted Multimedia Content: When Cryptography Meets Signal Processing
No full textThe processing and encryption of multimedia content are generally considered sequential and independent operations. In certain multimedia content processing scenarios, it is, however, desirable to carry out processing directly on encrypted signals. The field of secure signal processing poses significant challenges for both signal processing and cryptography research; only few ready-to-go fully integrated solutions are available. This study first concisely summarizes cryptographic primitives used in existing solutions to processing of encrypted signals, and discusses implications of the security requirements on these solutions. The study then continues to describe two domains in which secure signal processing has been taken up as a challenge, namely, analysis and retrieval of multimedia content, as well as multimedia content protection. In each domain, state-of-the-art algorithms are described. Finally, the study discusses the challenges and open issues in the field of secure signal processing.Electrical Engineering, Mathematics and Computer Scienc
Almost-Uniform Sampling of Points on High-Dimensional Algebraic Varieties
No full textWe consider the problem of uniform sampling of points on an algebraic variety. Specifically, we develop a randomized algorithm that, given a small set of multivariate polynomials over a sufficiently large finite field, produces a common zero of the polynomials almost uniformly at random. The statistical distance between the output distribution of the algorithm and the uniform distribution on the set of common zeros is polynomially small in the field size, and the running time of the algorithm is polynomial in the description of the polynomials and their degrees provided that the number of the polynomials is a constant
New model for rigorous analysis of LT-codes
No full textWe present a new model for LT codes which simplifies the analysis of the error probability of decoding by belief propagation. For any given degree distribution, we provide the first rigorous expression for the limiting bit-error probability as the length of the code goes to infinity via recent results in random hypergraphs by Darling and Norris, Ann. Appl. Probab., 2005. For a code of finite length, we provide an algorithm for computing the probability of block-error of the decoder. This algorithm improves by a linear factor the algorithm of Karp, Luby, and Shokrollahi, Proc. of ISIT, 2004.ALG
Raptor codes on symmetric channels
No full textThis paper extends the construction and analysis of Raptor codes originally designed in A. Shokrollahi (2004) for the erasure channel to general symmetric channels. We explicitly calculate the asymptotic fraction of output nodes of degree one and two for capacity-achieving Raptor codes, and discuss techniques to optimize the output degree distribution.ALG
A Monte-Carlo approach for pricing arithmetic Asian rainbow options under the mixed fractional Brownian motion
No full textWe derive a closed-form solution for pricing geometric Asian rainbow options under the mixed geometric frac-
tional Brownian motion (FBM). In particular, the number of underlying assets is allowed to be arbitrary, and fully
correlated fractional Brownian motions are taken into account. The analytical solution obtained is used as a con-
trol variate for Monte Carlo based computations of the price of arithmetic Asian rainbow options. Numerical ex-
periments are presented in which options on two, three, four and ten underlying assets are considered. Results
reveal that the proposed control variate technique is very effective to reduce the variance of the Monte Carlo es-
timator and yields a reliable approximation of the Asian rainbow option price
Characterization, crystal structure, and solution studies of a proton transfer compound obtained from 2,6-pyridinedicarboxylic acid and 1,4,10,13-tetraoxa-7,6-diazacyclooctadecane
No full textThe pro ton trans fer com pound, (DA18C6H2)(pydcH)2×0.25H2O, has been pre pared
from the re ac tion be tween 1,4,10,13-tetraoxa-7,16-diazacyclooctadecane,
diaza-18-crown-6 (DA18C6), and 2,6-pyridinedicarboxylic acid, dipicolinic acid
(pydcH2). The char ac ter iza tion was per formed us ing 1H and 13C NMR, IR spec tros copy
and sin gle crys tal X-ray dif frac tion anal y sis. The asym met ric unit con sists of one
(DA18C6H2)2+ cat ion adopt ing a sigmoidal con for ma tion which in ter acts with two
(pydcH)– an ions via hy dro gen bonds in volv ing the protonated amine groups of the
diazacrown ether. –COOH···–OOC– head-to-tail hy dro gen bonds gen er ate 2D un du lat -
ing lay ers along [100] and [001] in the crys tal lat tice. The protonation con stants of
DA18C6 and pydcH2 and equi lib rium con stants for the re ac tion of the two re ac tants were
de ter mined by potentiometric pH ti tra tion. The so lu tion stud ies sup ported the for ma tion
also in so lu tion of (DA18C6H2)(pydcH)2 as the most abun dant spe cies at pH = 3.4
A novel proton transfer self-associated compound from dipicolinic acid and guanidine and its Cadmium(II) complex: synthesis, characterization, crystal structure, and solution studies
No full textA novel 1:2 proton transfer self-associated compound LH2, (GH+)2(pydc2—), was synthesized from the reaction of dipicolinic acid, pydcH2, (2, 6-pyridinedicarboxylic acid), and guanidine hydrochloride, (GH+)(Cl—). The characterization was performed using IR, 1H and 13C NMR spectroscopy and single-crystal X-ray diffraction. LH2 · H2O crystallizes in the space group C2/c of the monoclinic system and contains eight molecules per unit cell. The unit cell dimensions are: a = 26.480(5)Å, b = 8.055(2)Å, c = 14.068(3)Å. The first coordination complex (GH)2[Cd(pydc)2] · 2H2O, was prepared using LH2 and cadmium(II) iodide, and characterized by 1H and 13C NMR spectroscopy and X-ray crystallography. The crystal system is triclinic with space group P1 ̄ with one molecule per unit cell. The unit cell dimensions are: a = 8.5125(7)Å, b = 11.0731(8)Å, c = 13.2404(10)Å. The cadmium(II) atom is six-coordinated with a distorted octahedral geometry. The two pydc2— units are almost perpendicular to each other. The protonation constants of the building blocks of the pydc-guanidine adduct, the equilibrium constants for the reaction of pydc2— with guanidine and the stoichiometry and stability of the Cd2+ complex with LH2 in aqueous solution were accomplished by potentiometric pH titration. The solution studies strongly support a self-association between pydc2— and GH+ with a stoichiometry for the CdII complex similar to that observed for the isolated crystalline complex. In fact, the [Cd(pydc)2]2— complex was found as the most abundant species in solution (> 90 %) at a pH >5
08301 Final Report – Group Testing in the Life Sciences
No full textGroup testing AKA smart-pooling is a general strategy for minimizing the number
of tests necessary for identifying positives among a large collection of items. It has the potential to efficiently identify and correct for experimental errors (false–positives and false–negatives). It can be used whenever tests can detect the presence of a positive in a group (or pool) of items, provided that positives are rare. Group testing has numerous applications in the life sciences, such as physical mapping, interactome mapping, drug–resistance screening, or designing DNA-microarrays, and many connections to computer science, mathematics and communications, from error-correcting codes to
combinatorial design theory and to statistics. The seminar brought together researchers representing the different communities working on group testing and experimentalists from the life sciences. The desired outcome of the seminar was a better understanding of the requirements for and the possibilities of group testing in the life sciences
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