102 research outputs found

    An overview of cryptosystems based on finite automata

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    Finite automata are backbones of the cryptosystems based on language theory. Most of the cryptosystems based on grammars and word problems are either insecure or do not satisfy digital signature prosperities. Basically, the cryptosystems based on automata are classified into cryptosystems based on: transducers, cellular automata and acceptors (i.e., finite automata without outputs). In this paper, we discuss the advantages and disadvantages of the important cryptosystems based on finite automata such as FAPKC, Gysin, Wolfram, Kari, Dӧmӧsi’s cryptosystems and modified Dӧmӧsi’s cryptosystems

    A novel cryptosystem based on Gluškov product of automata

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    The concept of Gluškov product was introduced by V. M. Gluškov in 1961. It was intensively studied by several scientists (first of all, by Ferenc Gécseg and the automata-theory school centred around him in Szeged, Hungary) since the middle of 60’s. In spite of the large number of excellent publications, no application of Gluškov-type products of automata in cryptography has arisen so far. This paper is the first attempt in this direction

    Graphic cryptography with pseudorandom bit generators and cellular automata

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    In this paper we propose a new graphic symmetrical cryptosystem in order to encrypt a colored image defined by pixels and by any number of colors. This cryptosystem is based on a reversible bidimensional cellular automaton and uses a pseudorandom bit generator. As the key of the cryptosystem is the seed of the pseudorandom bit generator, the latter has to be cryptographically secure. Moreover, the recovered image from the ciphered image has not loss of resolution and the ratio between the ciphered image and the original one, i.e., the factor expansion of the cryptosystem, is 11.Peer reviewe

    Secure Trapdoor Hash Functions Based on Public-Key Cryptosystems

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    In this paper we systematically consider examples representative of the various families of public-key cryptosystems to see if it would be possible to incorporate them into trapdoor hash functions, and we attempt to evaluate the resulting strengths and weaknesses of the functions we are able to construct. We are motivated by the following question: Question 1.2 How likely is it that the discoverer of a heretofore unknown public-key cryptosystem could subvert it for use in a plausible secure trapdoor hash algorithm? In subsequent sections, our investigations will lead to a variety of constructions and bring to light the non-adaptability of public-key cryptosystems that are of a \low density. More importantly, we will be led to consider from a new point of view the effects of the unsigned addition, shift, exclusive-or and other logical bit string operators that are presently used in constructing secure hash algorithms: We will show how the use of publickey cryptosystems leads to \fragile secure hash algorithms, and we will argue that circular shift operators are largely responsible for the security of modern high-speed secure hash algorithms

    Pseudorandom number generator by cellular automata and its application to cryptography.

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    by Siu Chi Sang Obadiah.Thesis (M.Phil.)--Chinese University of Hong Kong, 1999.Includes bibliographical references (leaves 66-68).Abstracts in English and Chinese.Chapter 1 --- Pseudorandom Number Generator --- p.5Chapter 1.1 --- Introduction --- p.5Chapter 1.2 --- Statistical Indistingushible and Entropy --- p.7Chapter 1.3 --- Example of PNG --- p.9Chapter 2 --- Basic Knowledge of Cellular Automata --- p.12Chapter 2.1 --- Introduction --- p.12Chapter 2.2 --- Elementary and Totalistic Cellular Automata --- p.14Chapter 2.3 --- Four classes of Cellular Automata --- p.17Chapter 2.4 --- Entropy --- p.20Chapter 3 --- Theoretical analysis of the CA PNG --- p.26Chapter 3.1 --- The Generator --- p.26Chapter 3.2 --- Global Properties --- p.27Chapter 3.3 --- Stability Properties --- p.31Chapter 3.4 --- Particular Initial States --- p.33Chapter 3.5 --- Functional Properties --- p.38Chapter 3.6 --- Computational Theoretical Properties --- p.42Chapter 3.7 --- Finite Size Behaviour --- p.44Chapter 3.8 --- Statistical Properties --- p.51Chapter 3.8.1 --- statistical test used --- p.54Chapter 4 --- Practical Implementation of the CA PNG --- p.56Chapter 4.1 --- The implementation of the CA PNG --- p.56Chapter 4.2 --- Applied to the set of integers --- p.58Chapter 5 --- Application to Cryptography --- p.61Chapter 5.1 --- Stream Cipher --- p.61Chapter 5.2 --- One Time Pad --- p.62Chapter 5.3 --- Probabilistic Encryption --- p.63Chapter 5.4 --- Probabilistic Encryption with RSA --- p.64Chapter 5.5 --- Prove yourself --- p.65Bibliograph
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