928 research outputs found

    Classification of Encryption Algorithms using Fisher’s Discriminant Analysis

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    Fisher’s Discriminant Analysis (FDA) is a method used in statistics and machine learning which can often lead to good classification between several populations by maximizing the separation between the populations. We will present some applications of FDA that discriminate between cipher texts in terms of a finite set of encryption algorithms. Specifically, we use ten algorithms, five each of stream and block cipher types. Our results display good classification with some of the features. In the present case we have little in terms of an existing standard; however, our limited study clearly shows that further exploration of this issue could be worthwhile

    Detection of nontrivial topology driven by charge density wave in a semi-Dirac metal

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    The presence of electron correlations in a system with topological order can lead to exotic ground states. Considering single crystals of LaAgSb2 which has a square net crystal structure, one finds multiple charge density wave transitions (CDW) as the temperature is lowered. We find large planar Hall (PHE) signals in the CDW phase, which are still finite in the high temperature phase though they change sign. Optimising the structure within first-principles calculations, one finds an unusual chiral metallic phase. This is because as the temperature is lowered, the electrons on the Ag atoms get more localized, leading to stronger repulsions between electrons associated with atoms on different layers. This leads to successive layers sliding with respect to each other, thereby stabilising a chiral structure in which inversion symmetry is also broken. The large Berry curvature associated with the low temperature structure explains the low temperature PHE. At high temperature the PHE arises from the changes induced in the tilted Dirac cone in a magnetic field. Our work represents a route towards detecting and understanding the mechanism in a correlation driven topological transition through electron transport measurements, complemented by ab-initio electronic structure calculations.Comment: 11 pages, 4 figures, Includes supplementary information, Accepted in Advanced Functional Material
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