Effective software-oriented cryptosystem in complex PC security software

To ensure high encryption rate and good data security, an organization of an encipherement program in the form of two modules was proposed. The first module is used for customizing the second one, the latter being the resident of the program, which maintains all application calls about encryption procedures. This approach is shown to be perspective for the elaboration of the cryptosystems with indefinite cryptalgorithm. Several typical software-oriented cryptoschemes are considered. The developed cryptomodules have high encipherement rate (2-10 Mbps for Intel 386) and secure high information protection level Organization of a new computer security software complex COBRA is considered. High enciphering rate and good data protection are provided by the resident cryptomodule using less than 1 kbyte of the main memory and working in dynamic encryption mode

Structural and vibrational properties of CdAl2S4 under high pressure: Experimental and theoretical approach

"This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp5037926.”The behavior of defect chalcopyrite CdAl2S4 at high pressures and ambient temperature has been investigated in a joint experimental and theoretical study. High-pressure X-ray diffraction and Raman scattering measurements were complemented with theoretical ab initio calculations. The equation of state and pressure dependences of the structural parameters of CdAl2S4 were determined and compared to those of other AB(2)X(4) ordered-vacancy compounds. The pressure dependence of the Raman-active mode frequencies is reported, as well as the theoretical phonon dispersion curves and phonon density of states at 1 atm. Our measurements suggest that defect chalcopyrite CdAl2S4 undergoes a phase transition above 15 GPa to a disordered-rocksalt structure, whose equation of state was also obtained up to 25 GPa. In a downstroke from 25 GPa to 1 atm, our measurements indicate that CdAl2S4 does not return to the defect chalcopyrite phase; it partially retains the disordered-rocksalt phase and partially transforms into the spinel structure. The nature of the spinel structure was confirmed by the good agreement of our experimental results with our theoretical calculations. All in all, our experimental and theoretical results provide evidence that the spinel and defect chalcopyrite phases of CdAl2S4 are competitive at 1 atm. This result opens the way to the synthesis of spinel-type CdAl2S4 at near-ambient conditions.Financial support from the Spanish Consolider Ingenio 2010 Program (Project CSD2007-00045) is acknowledged. This work was also supported by Spanish MICCIN under Project MAT2010-21270-C04-03/04 and by Vicerrectorado de Investigacion de la Universitat Politecnica de Valencia under Projects UPV2011-0914 PAID-05-11 and UPV2011-0966 PAID-06-11. Supercomputer time was provided by the Red Espanola de Supercomputacion (RES) and the MALTA cluster. J.A.S. acknowledges the Juan de la Cierva fellowship program for financial support. AM. and P.R.-H. acknowledge S. Munoz Rodriguez for providing a data-parsing application.Sans Tresserras, JÁ.; Santamaría Pérez, D.; Popescu, C.; Gomis, O.; Manjón Herrera, FJ.; Vilaplana Cerda, RI.; Muñoz, A.... (2014). Structural and vibrational properties of CdAl2S4 under high pressure: Experimental and theoretical approach. Journal of Physical Chemistry C. 118(28):15363-15374. https://doi.org/10.1021/jp5037926S15363153741182

Fast software encryption system based on local pseudorandomness

New software-oriented single key cryptosystem based on local pseudorandomness is considered. Its cryptorobustness is characterized in probabilistic terms. The minimal size of the known (chosen) plaintext has been estimated to be >3·1031(>1021) bytes the cryptorobustness being >1057 (>1037) operations

Finite Non-Commutative Associative Algebras as Carriers of Hidden Discrete Logarithm Problem

The article introduces new finite algebras attractive as carriers of the discrete logarithm problem in a hidden group. In particular new 4-dimensional and 6-dimensional finite non-commutative algebras with associative multiplication operation and their properties are described. It is also proposed a general method for defining finite non-commutative associative algebras of arbitrary even dimension m ≥ 2. Some of the considered algebras contain a global unit, but the other ones include no global unit element. In the last case the elements of the algebra are invertible locally relatively local bi-side units that act in the frame of some subsets of elements of algebra. For algebras of the last type there have been derived formulas describing the sets of the (right-side, left-side, and bi-side) local units. Algebras containing a large set of the global single-side (left-side and right-side) units and no global bi-side unit are also introduced. Since the known form of defining the hidden discrete logarithm problem uses invertibility of the elements of algebra relatively global unit, there are introduced new forms of defining this computationally difficult problem. The results of the article can be applied for designing public-key cryptographic algorithms and protocols, including the post-quantum ones. For the first time it is proposed a digital signature scheme based on the hidden discrete logarithm problem.Статья рассматривает новые конечные алгебры, представляющие интерес в качестве носителей задачи дискретного логарифмирования в скрытой группе. В частности, предложены новые 4-мерные и 6-мерные конечные некоммутативные алгебры с ассоциативной операцией умножения и описаны их свойства. Также предложен общий метод задания конечных некоммутативных ассоциативных алгебр произвольной четной размерности mge 2. Некоторые из рассмотренных алгебр содержат глобальную двухстороннюю единицу, а другие не содержат такой единицы. В последнем случае элементы алгебры обратимы локально относительно некоторой локальной двухсторонней единицы, действующей в рамках некоторого подмножества элементов алгебры. Для алгебр последнего типа выведены формулы, описывающие множества правосторонних, левосторонних и двухсторонних локальных единиц. Также представлены алгебры, содержащие большое множество глобальных левосторонних (правосторонних) единиц при отсутствии в них глобальной двухсторонней единицы. Поскольку известные формы задания крытой задачи дискретного логарифмирования используют обратимость элементов алгебры относительно глобальной двухсторонней единицы, были предложены новые формы задания этой вычислительно трудной задачи. Результаты статьи могут быть использованы для разработки криптографических алгоритмов и протоколов с открытым ключом, включая постквантовые криптосхемы. Впервые предложена схема цифровой подписи, основанная на скрытой задаче дискретного логарифмирования

Software encryption: new 64-bit block cryptoscheme

There are considered new fast software encryption function and some its cryptographical properties. It has been shown that the probability of the selection of two equivalent keys is very low. Crypto-robustness of this cipher has been evaluated on the basis of its probabilistic model

On Multiple Symmetric Fixed Points in GOST

In this article the author revisits the oldest attack on GOST known, the Kara Reflection attack, and another totally unrelated truncated differential attack by Courtois and Misztal. It is hard to imagine that there could be any relationship between two so remote attacks which have nothing in common. However, there is one: Very surprisingly, both properties can be combined and lead the fastest attack on GOST ever found, which is nearly feasible to execute in practice