Wyniki wyszukiwania - BazTech

1

Optimal steganographic method based on image encryption

Al-Bdour Nashat, Mansour Ayman M.

Przegląd Elektrotechniczny

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2021

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R. 97, nr 6

10--14

EN

The paper investigates an image encryption method for the implementation of steganographic information protection. This paper aims to increase the volume of a secret message with fixed sized image. The proposed system represents an image in the form of a binary code. Each pixel code consists of 24 bits, which encode blue, green and red colors. The resulting image code is encrypted using a key set of encrypt codes generated by a pseudo-random number generator. The generation is based on cellular automata with active cells. As a result, the best bits in the color bytes of each pixel have been identified. The method provides a high degree of encryption due to the fact that, in addition to encrypting the selected bits of the pixel codes, the codes are changed due to the introduction of the bits of the secret message. The bits of the secret message have a random order since the secret message is determined by its internal content. Each new message is different from other messages and is additionally encrypted. This makes it possible to use several encrypt keys in conceal a message in an image.

PL

W artykule omówiono metodę szyfrowania obrazu w celu realizacji steganograficznej ochrony informacji. Ten artykuł ma na celu zwiększenie objętości tajnej wiadomości z obrazem o stałym rozmiarze. Proponowany system przedstawia obraz w postaci kodu binarnego. Każdy kod piksela składa się z 24 bitów, które kodują kolory niebieski, zielony i czerwony. Wynikowy kod obrazu jest szyfrowany przy użyciu zestawu kluczy szyfrujących kodów generowanych przez generator liczb pseudolosowych. Generacja oparta jest na automatach komórkowych z aktywnymi komórkami. W rezultacie zidentyfikowano najlepsze bity w bajtach koloru każdego piksela. Metoda zapewnia wysoki stopień szyfrowania dzięki temu, że oprócz szyfrowania wybranych bitów kodów pikselowych, kody ulegają zmianie w wyniku wprowadzenia bitów tajnej wiadomości.

2

Management of the spare parts storage in the production process using the monte carlo method

Ślaski Paweł

Quality Production Improvement - QPI

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2019

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Vol. 1, Iss. 1

261--267

EN

The article presents the methodology of controlling stock of spare parts during short-run production of current equipment. A pseudo-random number generator has been developed, whose main task is to estimate the expected value E (Y) of the random variable Y which is the number of exchanges of a spare part of a particular equipment. By means of a Monte Carlo computer simulation, pseudo-random numbers are generated with a uniform distribution from the interval (0.1). These numbers, based on the cumulative distribution inversion method, are transformed into a form of distribution that uniquely determines the optimal size of spare parts.

3

Comparing quality of pseudo- and true-random numbers obtained from different sources

Wiśniewska J.

Symulacja w Badaniach i Rozwoju

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2018

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Vol. 9, nr 1-2

73--82

EN

The manuscript refers to the problem of the pseudorandom numbers generation. Numbers needed during a simulation may be generated by pseudorandom numbers generators but also by true random numbers generators or digital random number generators. In this work some tests were described which help to evaluate quality of random values. For five generators, the batteries of tests were run and the manuscript contains results of these tests in a form of graphs.

PL

Praca dotyczy problemu generowania liczb pseudolosowych. Wartości liczbowe wymagane podczas symulacji mogą być generowane przez: pseudolosowe generatory liczb, rzeczywiste generatory liczb losowych lub cyfrowe generatory liczb losowych. W artykule opisano zestaw testów, które pomagają w ocenie jakości uzyskiwanych wartości liczbowych. Dla pięciu różnych generatorów uruchomiono zestaw testów, a w pracy zamieszczono wyniki tych testów w postaci wykresów.

4

Implementation of modified additive lagged Fibonacci generator

Mandrona M. M., Maksymovych V. M., Harasymchuk O. I., Kostiv Y. M.

Challenges of Modern Technology

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2016

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Vol. 7, no. 1

3--6

EN

Generator of pseudorandom bit sequence with increased cryptographic security, which is based on additive lagged Fibonacci generator, is developed. The generator structure circuit and it work principle are described in the paper. There are also given two variants of it construction that are formed on programmable logic device developed by Xilinx company. The main generator characteristics are researched, in particular: recurrence period, fastacting, statistical characteristics. In relation to the last the statistical portrait is presented, that was built with the help of NIST tests.

5

Pipelined pseudo-random number generator with the efficient post-processing method

Dąbal P.

International Journal of Microelectronics and Computer Science

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2015

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Vol. 6, nr 2

43--48

EN

This brief proposes a novel architecture of the chaotic pseudo-random bit generators (PRBGs) based on the chaotic nonlinear model and pipelined data processing. We investigated PRBG built on the chaotic logistic map and frequency dependent negative resistances (FDNR). A significant enhancement in terms of output throughput has been achieved by combining the advantages of pipelining with post-processing based on fast logical operations like bit shifting and XOR. The proposed method has been implemented using programmable SoC Zynq device from Xilinx. We verified output pseudo-random bit stream by standard statistical tests NIST SP800-22. We also present detailed comparison of the proposed post-processing method with the methods reported previously by the other authors. In particular, we compared the maximum output throughput and amount of total logical resources required by PRBG implementation in the programmable SoC device. For PRBGs based on the logistic chaotic map and frequency dependent negative resistance (FDNR) we obtained speed-up factors equal to 33% and 14%, respectively. By composing the output stream of 3 data channels in PRBG with FDNR element, we get the maximum throughput equal to 38.43 Gbps. That is significantly greater comparing to the chaotic PRBGs described so far.

6

Implementacja multiplikatywnych generatorów kongruencyjnych z modulnikiem w układzie FPGA

Jaworski M., Jessa M.

Elektronika : konstrukcje, technologie, zastosowania

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2014

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Vol. 55, nr 12

14-16

PL

W pracy opisano uniwersalną metodę implementacji rodziny generatorów pseudolosowych bazujących na multiplikatywnym generatorze kongruencyjnym z modulnikiem 231 -1. Algorytm optymalizuje zarówno operację modulo jaki i operację mnożenia. Projekt został przygotowany w języku Verilog i zaimplementowany w układzie programowalnym FPGA (ang. Field Programmable Gate Array) o symbolu XC6SLX45 firmy Xilinx. Pojedynczy generator zajmuje około 130 komórek typu Slice i może wytwarzać ciąg pseudolosowy o szybkości 4.169 Gbits na sekundę. Zaimplementowany generator nie jest generatorem bezpiecznym, ale może zostać wykorzystany w kryptografii po dodatkowym przetworzeniu ciągu wyjściowego.

EN

A universal hardware implementation of a pseudorandom number generators family based on a multiplicative congruential generator (MCG) with modulus 231 -1 has been proposed in this paper. The proposed algorithm optimizes both the multiplication and modulo 231 -1 operation. The design was prepared in Verilog and implemented in Xilinx Field Programmable Gate Array (FPGA) device XC6SLX45. A single generator takes up about 130 slices and can produce up to 4.169 Gbits per second. Implemented generators are not secure themselves, but they can be used in cryptography with additional processing and by using several different generators in parallel.

7

Professor Ryszard Zieliński's contribution to Monte Carlo methods and random number generators. Uniform asymptotics in statistics

Niemiro W.

Mathematica Applicanda

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2012

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Vol. 40, No. 2

92--106

PL

The aim of the paper is to summarize contributions of Ryszard Zieliński to two important areas of research. First, we discuss his work related to Monte Carlo methods. Ryszard Zieliński was particularly interested in Monte Carlo optimization. About 10 of his papers concerned stochastic algorithms for seeking extrema. He examined methods related to stochastic approximation, random search and global optimization. We stress that Zielinski often considered computational problems from a statistical perspective. In several articles he explicitly indicated that optimization can be reformulated as a statistical estimation problem. We also discuss relation between the family of Simulated Annealing algorithms on the one hand and some procedures examined earlier by Ryszard Zieliński on the other. Another topic belonging to Monte Carlo methods, in which Ryszard Zieliński has achieved interesting results, is construction of random number generators and examination of their statistical properties. Zieliński proposed an aperiodic generator based on Weil sequences and showed how it can be efficiently implemented. Later he constructed an algorithm which uses several such generators and produces pseudo-random sequences with better statistical properties. The second area of Zieliński’s work discussed here is related to uniform limit theorems of mathematical statistics. We stress the methodological motivation behind the research in this direction. In Zieliński’s view, asymptotic results should hold uniformly with respect to the family of probability distributions under consideration. In his opinion, this requirement comes from the very nature of statistical models and the needs of practical applications. Zieliński examined uniform versions the Weak Law of Large Numbers, Strong Law of Large Numbers and Central Limit Theorem in several statistical models. Some results were rather unexpected. He also gave a necessary and sufficient condition for uniform consistency of sample quantiles. Two papers of Ryszard Zieliński were devoted to uniform consistency of smoothed versions of empirical cumulative distribution function. In one of them he proved a version of Dvoretzky-Kiefer-Wolfowitz inequality. The aim of the paper is to summarize contributions of Ryszard Zieliński to two important areas of research. First, we discuss his work related to Monte Carlo methods. Ryszard Zieliński was particularly interested in Monte Carlo optimization. About 10 of his papers concerned stochastic algorithms for seeking extrema. He examined methods related to stochastic approximation, random search and global optimization. We stress that Zielinski often considered computational problems from a statistical perspective. In several articles he explicitly indicated that optimization can be reformulated as a statistical estimation problem. We also discuss relation between the family of Simulated Annealing algorithms on the one hand and some procedures examined earlier by Ryszard Zieliński on the other. Another topic belonging to Monte Carlo methods, in which Ryszard Zieliński has achieved interesting results, is construction of random number generators and examination of their statistical properties. Zieliński proposed an aperiodic generator based on Weil sequences and showed how it can be efficiently implemented. Later he constructed an algorithm which uses several such generators and produces pseudo-random sequences with better statistical properties. The second area of Zieliński’s work discussed here is related to uniform limit theorems of mathematical statistics. We stress the methodological motivation behind the research in this direction. In Zieliński’s view, asymptotic results should hold uniformly with respect to the family of probability distributions under consideration. In his opinion, this requirement comes from the very nature of statistical models and the needs of practical applications. Zieliński examined uniform versions the Weak Law of Large Numbers, Strong Law of Large Numbers and Central Limit Theorem in several statistical models. Some results were rather unexpected. He also gave a necessary and sufficient condition for uniform consistency of sample quantiles. Two papers of Ryszard Zieliński were devoted to uniform consistency of smoothed versions of empirical cumulative distribution function. In one of them he proved a version of Dvoretzky-Kiefer-Wolfowitz inequality.

8

Modelowanie charakterystyki generatora liczb pseudolosowych

Frydrych M.

Zeszyty Naukowe Wyższej Szkoły Informatyki

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2008

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Vol. 7, Nr 1

29-38

PL

W pracy przedstawiono metody wykorzystania klasycznego generatora liczb pseudolosowych o jednostajnym rozkładzie gęstości prawdopodobieństwa dla modelowania charakterystyk niejednostajnych spotykanych w zastosowaniach praktycznych. Zaprezentowano metody typu analitycznego jak i probablistycznego. Modelowanie odbywa się głównie na poziomie praktycznym pod kontrolą teoretycznej znajomości zachodzących zjawisk.

EN

This article presents methods of modeling ununiform distributions of probability density by classical pseudo-random number generator (PRNG) with uniform characteritic. The methods given are based on analytic and probability models.

9

Przydatność generatorów liczb pesudolosowych do analizy przepływu ciepła metodą Monte Carlo

Adrianowicz K., Rudnicki Z.

Zeszyty Naukowe. Matematyka - Fizyka / Politechnika Śląska

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1999

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z. 84

7-31

PL

Trzy generatory liczb psudolosowych: Randu, Urand1 i Urand2, zostały poddane statystycznym testom zgodności rozkładu oraz testom wykorzystującym zadania kontrolne, w celu wybrania generatora najlepiej nadającego się do analizy przepływu ciepła metodą Monte Carlo. Na podstawie otrzymanych wyników za najbardziej przydatny uznano generator Urand2.

EN

Three random number generators: Randu, Urand1, Urand2 were subject to statistical tests of goodness of fit as well as to tests that made use of control research. The aim of these tests was to select the generator which is most suitable for the heat transfer analysis useing the Monte Carlo method. The results achieved showed that the most useful generator is Urand2.