20 results on '"Finite field"'
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2. On the Orders of the Elements of a Square Extension of a Finite Field of Characteristic 2
- Author
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Valery Maximov and Victoria Remezova
- Subjects
finite field ,characteristic 2 ,order of element ,square extension over a field ,irreducible polynomial ,recursive sequence ,generating series ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
Let F(2m) will be an arbitrary finite field of characteristic 2. It’s square extension will be considered as an algebra with basiс elements 1 and e over the field F(2m). Here 1 is considered as the unit element of the algebra, and e satisfies the relation: e2 = e + α. An element α maybe arbitrary from the field F(2m), but it is not satisfying to the condition α = x + x2 for some x element from F(2m). Let us n0 (α) denote the order of basis element e. Then the main result of the paper can be formulated as: The irreducible polynomial 1 + t + αt2 divides the polynomial 1 + tn if and only the order if n0 (α) divides a natural n. The similar results for arbitrary elements of field F(2m) follow from main theorem. The proof of main result based on the properties of the recurrence relations between the polynomials Pn (α) and Qn (α), definite for all n = 0, 1, 2, … by the relations en = Pn (α) + Qn (α) e. The formulas for the generating series of these polynomials contain the most important such properties. The formulas were obtained.
- Published
- 2020
- Full Text
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3. CALCULATION OF THE MINIMUM DEGREE OF A POLYNOMIAL OVER A FINITE FIELD FOR A VECTOR BOOLEAN MAP GIVEN IN ANF
- Author
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Sergey A. Belov
- Subjects
Finite Field ,Boolean Function ,Trace Form ,Interpolation Cryptanalysis ,SAT-Solvers ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
We consider vector mappings over the set of 0 and 1 given by the set of Boolean functions. Boolean functions included in the map are given in ANF. Having fixed the rule according to which the binary vectors are associated with the elements of a finite field of characteristic two, we obtain a one-to-one correspondence between the mappings of the vector space into itself and the functions over the finite field. The finite field is considered as a ring of polynomials with the operations of addition and multiplication modulo the selected irreducible polynomial. It is known that any function over a finite field can be written as a polynomial. Moreover, for various irreducible polynomials, the polynomials over a finite field, corresponding to a given vector map, may in general be different and have different properties. We consider the problem of finding an irreducible polynomial such that the degree of a polynomial over a finite field is minimal, provided that the correspondence between binary vectors and elements of a finite field is given by using a polynomial basis of a finite field. We present an algorithm to solve this problem. Firstly we rewrite Boolean functions in trace form and calculate expressions for finite field polynomial coefficients. Then we calculate elements of dual basis as an expression of polynomial basis. Using them we obtain system pf Boolean equations. Finally we solve system of Boolean equations by SAT-solver and filter reducible polynomials. We estimate of the complexity of obtaining the specified system of Boolean equations is bitwise operations.
- Published
- 2019
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4. Perfect verification of modular scheme
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Gennadii V. Matveev and Vladislav V. Matulis
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polynomial modular scheme ,secret sharing ,verification ,secret ,partial secret ,finite field ,Mathematics ,QA1-939 - Abstract
Secret sharing schemes are used to distribute a secret value among a group of users so that only authorized set of them can reconstruct the original secret correctly. The modular secret sharing scheme (MSSS) we are studying is based on the Chinese Remainder Theorem. In this scheme the secrets s(x), S(x), s1(x),…, sk(x) are defined as follows s(x) = S(x) = mod m(x), si(x) = S(x) mod mi(x), i = 1, 2, …, k. All the secrets and moduli are chosen from polynomial ring Fp[x], and the reconstruction of secret s(x) is carried out by applying the above-mentioned Chinese Remainder Theorem. The verification of any secret sharing scheme is understood as the protocol of verification by the participants of their partial secrets and (or) the protocol for verifying the legitimacy of the actions of the dealer. In this paper, we introduce a perfect verification protocol of MSSS. It means that none information leaks under distribution and verification. Two verification protocols are introduced in this paper. The first one is simpler and it depends on assumption about dealer honesty. If there is no such assumption verification is more complex. Both protocols are based on one work by J. Benalo and generalize the protocol proposed earlier by M. Vaskovsky and G. Matveev in two ways. First, the general, not only the threshold access structure is verified, and secondly, the dealer is not necessarily honest. Earlier, N. Shenets found the perfection condition of MSSS. Thus, if these conditions аre met, both the MSSS and its verification protocol are perfect.
- Published
- 2018
5. Verification of modular secret sharing
- Author
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Maksim M. Vaskouski and Gennadii V. Matveev
- Subjects
polynomial modular scheme ,secret ,partial secret ,finite field ,Mathematics ,QA1-939 - Abstract
In the present paper new scheme of secret verification are constructed. Verification with trusted party participation is conducted with help of an external device, which takes an arbitrary polynomial S(x), input element x0 ∈ Fpn and returns a value ξS(x0), where ξ is an Fpn – valued uniformly distributed random variable. It is shown that using of such device allows any user to verify his secret. Polynomial verification scheme is based on verification of divisibility g(x)|f(x) in the ring Z[x]. Only a value of polynomial S(x) in unknown point x = l is disclosed at the proposed verification method. Benaloh’s verification of the modular scheme allows any shareholder to ensure in consistency of all partial secrets, i. e. any legal group of shareholders can restore the secret S(x) correctly. None information about the secret S(x), excepting a prior information, is disclosed. The proposed protocols can be used safely for schemes over arbitrary finite fields without additional restrictions on a size of a filed.
- Published
- 2018
6. Lower Bound of the Complexity of Seven-Valued Functions in the Class of Polarized Polynomials
- Author
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A.S. Baliuk and A.S. Zinchenko
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finite field ,polarized polynomial ,Kroneker form ,complexity ,lower bounds ,Mathematics ,QA1-939 - Abstract
One of the directions of the investigation of functions over finite fields is the study of their representations, including polynomial ones. In the area of polynomial representations of functions the problem of estimating the complexity of such representations can be highlighted. The complexity of the polynomial, representing the function, is the number of its nonzero terms. Each function can be represented by several different polynomials from the same class. The complexity of a function in the class of polynomials is the least possible complexity of a polynomial from this class, representing the function. The complexity of the given set of functions in the class of polynomials is the maximal complexity of a function from the set in this class of polynomials. In the case of functions over a finite field of order 2 (Boolean functions), exact values of the complexity of such representations are known for many classes of polynomial forms. But for functions over finite fields of order greater than two, even in fairly simple classes of polynomials, only mismatched upper and lower bounds of complexity have been found. This paper is devoted to the study of the representation of seven-valued functions by polarized polynomials. The polynomials of this class have the form of a sum of a finite number of products of a certain type. For the case of Boolean and three-valued functions, effective lower bounds for the complexity in the class of polarized polynomials are known, as well as a weaker power estimate for functions over a finite field of prime order. In previous papers, the authors obtained effective lower bounds for the complexity of functions over finite fields of order 4 and 5 in the class of polarized polynomials. In this paper an effective lower bound for the complexity of seven-valued functions in the class of polarized polynomials has been obtained.
- Published
- 2017
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7. On upper bounds of the complexity of functions over nonprime finite fields in some classes of polarized polynomials
- Author
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A. Kazimirov and S. Reymerov
- Subjects
finite field ,polynomial ,polarized polynomial ,complexity ,Mathematics ,QA1-939 - Abstract
Recently, the interest to polynomial representations of functions over finite fields and over finite rings is being increased. Complexity of those representations is widely studied. This paper introduces new upper bounds on complexity of discrete functions over particular finite fields in class of polarized polynomials. The results are state in the terms of matrix forms. A matrix form is representation of functions vector of values as a product of nonsingular matrix and a vector of coefficients. The complexity of matrix form of a special kind is equal to complexity of polarized polynomial for same function. A complexity of a matrix form is a number of nonzero coefficients in its vector. Every function can be represented by variety of matrix forms of the same class. A complexity of a function in a class of matrix forms is the minimal complexity of forms in the class representing this function. This paper introduces new upper bounds on complexity of functions in class of polarized polynomials over fields of orders $2^k$ and $p^k$, $p$ is prime and $p \geqslant 3$.
- Published
- 2016
8. Lower Bound of the Complexity of Functions over Finite Field of Order 4 in the Class of Polarized Polynomials
- Author
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A. Baliuk and A.S. Zinchenko
- Subjects
finite field ,polarized polynomial ,Kroneker form ,complexity ,lower bounds ,Mathematics ,QA1-939 - Abstract
The representations, including polynomial, of functions over final fields have been actively investigated. The complexity of such representations is the main stream of research. Polynomial representations of Boolean functions have been studied well enough. The exact values of the complexity have been found for a lot of polynomial classes. Recently, the interest to polynomial representations of functions over finite fields and over finite rings is being increased. There are a lot of difficulties in studying of the complexity of these representations. Only not equal upper and lower bounds has been obtained, even for sagnificantly simple classes of polynomials. This paper is about polarized polynomials over finite field of order 4. Such a polynomial is a finite sum of products. Every polynomial represents an n-variable function over finite field. A complexity of a polynomial is a number of nonzero summands in it. Every function can be represented by several polynomials, which are belongs to the same class. A complexity of a function in a class of polynomials is the minimal complexity of polynomials in the class, which represent this function. Previously, the constructive lower bounds in the class of polarized polynomials have been known only for the case of Boolean and three-valued functions. Also, the weaker, non-constructive lower bound has been known for the case of functions over arbitrary prime finite field. In this paper the constructive lower bound has been obtained for functions over finite field of order 4 in the class of polarized polynomials. The lower bound is equivalent to previously known lower bound for Boolean and three-valued functions.
- Published
- 2016
9. Upper Bounds of the Complexity of Functions over Finite Fields in Some Classes of Kroneker Forms
- Author
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A.S. Baliuk and G.V. Yanushkovsky
- Subjects
finite field ,polynomial ,Kroneker form ,complexity ,Mathematics ,QA1-939 - Abstract
Polynomial representations of Boolean functions have been studied well enough. Recently, the interest to polynomial representations of functions over finite fields and over finite rings is being increased. There are a lot of difficulties in studying of the complexity of these representations. Only not equal upper and lower bounds has been obtained, even for sagnificantly simple classes of polynomials. This paper is about polarized polynomials over finite fields and their generalizations: differentially and generically polarized polynomials. Such a polynomial is a finite sum of products. The difference between classes of polynomials is in constraints, applied to the products. Every polynomial represents an $n$-variable function over finite field. A complexity of a polynomial is a number of nonzero summands in it. Every function can be represented by several polynomials, which are belongs to the same class. A complexity of a function in a class of polynomials is the minimal complexity of polynomials in the class, which represent this function. Previously, the upper bounds were known for arbitrary $n$-variable function over primary finite field of order, greater than 2, for the classes of polarized and differentially polarized polynomials, as well as for the class of generically polarized polynomials. A representation of an $n$-ary function over finite field of order $q$ by a polarized polynomial or its generalization can be considered as a Kroneker form. This means, that the function, considered as a vector in appropriate linear space, is computed by a linear transformation of a vector of coefficients of the polynomial, where the matrix of this linear transformation is a Kroneker product of $n$ nonsingular matrices with rank $q$. This approach helped us to improve the upper bound for polarized and differentially polarized polynomials for the case of any finite field of odd order, and to improve the upper bound for generically polarized polynomials for the case of any finite field of order, greater than 2.
- Published
- 2015
10. On Upper Bound of the Complexity of Quasi Polynomial Representations of Functions over Finite Fields
- Author
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A.S. Baliuk
- Subjects
finite field ,polynomial ,quasi polynomial ,complexity ,Mathematics ,QA1-939 - Abstract
Representations of functions over finite fields, including polynomial representations, are being actively investigated. The complexity of such representations is one of main directions of research. This paper is about quasi polynomial complexity of functions over finite fields. Quasi polynomial can be considered as a regular polynomial with the following transformation: every occurence xi0, . . . , xik−1 of selected variable xi is replaced by a function from a set {g0(xi), . . . , gk−1(xi)} of linearly independent unary functions. The number of terms, the number of occurences of variables, or the degree of a polynomial are usually used as a measure of complexity. In the case of quasi polynomials one can use the number of terms as a natural measure of complexity, while further generalization are required for the number of occurences of variables and the degree of a polynomial. In this paper the number of terms is used as a measure of complexity. Previously, the upper bound of such a complexity was known for polynomials over finite fields of prime order. Namely, the quasi polynomial complexity of n-ary function over finite field of prime order k is at most k·kn/(k+1). In this paper an upper bound for the quasi polynomial complexity of functions over finite fields of arbitrary order q has been obtained, which significantly improves previously known upper bound for modulo prime quasi polynomials, if q ≥ 3. Namely, the quasi polynomial complexity of any n-ary function over finite field of order q is at most (q-1)·qn/(q-q1-q)
- Published
- 2014
11. The study of arithmetic of finite discrete groups corresponding to polynomials of a given degree
- Subjects
многоÑлен ,Galois field ,конеÑное поле ,polynomials ,замкнÑÑоÑÑÑ ,поле ÐалÑа ,closure ,finite field - Abstract
Тема вÑпÑÑкной квалиÑикаÑионной ÑабоÑÑ Â«ÐÑÑледование аÑиÑмеÑики конеÑнÑÑ Ð´Ð¸ÑкÑеÑнÑÑ Ð³ÑÑпп, ÑооÑвеÑÑÑвÑÑÑÐ¸Ñ Ð¿Ð¾Ð»Ð¸Ð½Ð¾Ð¼Ð°Ð¼ заданной ÑÑепени». Рданной ÑабоÑе ÑаÑÑмоÑÑÐµÐ½Ñ Ð¾ÑновнÑе аÑиÑмеÑиÑеÑкие опеÑаÑии в конеÑнÑÑ Ð¿Ð¾Ð»ÑÑ . Ð ÑабоÑе пÑедÑÑавлена пÑогÑамма Ð´Ð»Ñ ÑаÑÑеÑа непÑиводимÑÑ Ð¿Ð¾Ð»Ð¸Ð½Ð¾Ð¼Ð¾Ð² заданной ÑÑепени. Ðа оÑнове ÑÑÐ¸Ñ Ð¿Ð¾Ð»Ð¸Ð½Ð¾Ð¼Ð¾Ð² ÑÑÑоÑÑÑÑ Ð¿Ð¾Ð»Ñ ÐалÑа, ÑооÑвеÑÑÑвенно ÑÑепени многоÑлена и ÑÑÑоÑÑÑÑ ÑаблиÑÑ ÑÐ¼Ð½Ð¾Ð¶ÐµÐ½Ð¸Ñ Ð¸ ÑÑепеней. Ðа оÑнове полÑÑеннÑÑ ÑезÑлÑÑаÑов пÑоводиÑÑÑ Ð°Ð½Ð°Ð»Ð¸Ð· ÑвойÑÑв конеÑнÑÑ Ð³ÑÑпп и Ð¸Ñ Ð¸ÑÑледование на замкнÑÑоÑÑÑ., The topic of the final qualifying work is "The study of arithmetic of finite discrete groups corresponding to polynomials of a given degree". In this paper, the basic arithmetic operations in finite fields are considered. The paper presents a program for calculating irreducible polynomials of a given degree. On the basis of these polynomials, Galois fields are constructed, according to the degree of the polynomial, and multiplication tables and degrees are constructed. Based on the results obtained, the properties of finite groups are analyzed and their study for closure is carried out.
- Published
- 2022
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12. On groups with a strongly embedded unitary subgroup
- Author
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Anatoliy Sozutov
- Subjects
Physics ,Group (mathematics) ,General Mathematics ,Order (ring theory) ,Group Theory (math.GR) ,Type (model theory) ,Unitary state ,Combinatorics ,Mathematics::Group Theory ,Finite field ,Subgroup ,Borel subgroup ,FOS: Mathematics ,Element (category theory) ,Mathematics - Group Theory - Abstract
The proper subgroup $B$ of the group $G$ is called {\it strongly embedded}, if $2\in\pi(B)$ and $2\notin\pi(B \cap B^g)$ for any element $g \in G \setminus B $ and, therefore, $ N_G(X) \leq B$ for any 2-subgroup $ X \leq B $. An element $a$ of a group $G$ is called {\it finite} if for all $ g\in G $ the subgroups $ \langle a, a^g \rangle $ are finite. In the paper, it is proved that the group with finite element of order $4$ and strongly embedded subgroup isomorphic to the Borel subgroup of $U_3(Q)$ over a locally finite field $Q$ of characteristic $2$ is locally finite and isomorphic to the group $U_3(Q)$. Keywords: A strongly embedded subgroup of a unitary type, subgroups of Borel, Cartan, involution, finite element., Comment: 8 pages, in Russian
- Published
- 2020
13. О порядках элементов квадратичного расширения конечного поля характеристики 2
- Subjects
характеристика 2 ,квадратичное расширение поля ,производящий ряд ,рекуррентная последовательность ,discrete logarithm ,порядок элемента ,неприводимый полином ,characteristic 2 ,Finite field ,irreducible polynomial ,дискретный логарифм ,square extension over a field ,generating series ,order of element ,конечное поле ,recursive sequence - Abstract
Пусть F(2m) произвольное поле характеристики 2, его квадратичное расширение мы будем рассматривать как алгебру с базисом 1, e над полем F(2m). Здесь 1 рассматривается как единичный элемент алгебры, а элемент e удовлетворяет соотношению e2=e+α. Элемент может быть произвольным из поля F(2m), но неудовлетворяющий условию α=x+ x2 при некотором x из F(2m). Пусть n0(α) обозначает порядок элемента e. Тогда основной результат работы можно сформулировать так: Неприводимый полином 1+t+ αt2 делит полином 1+ tn тогда и только тогда, когда n0(α) делит натуральное n. Аналогичные результаты для произвольных элементов поля F(22m) следуют из этого. Доказательство базируется на свойствах рекуррентных соотношений между полиномами Pn и Qn, определяемые для всех n=0,1,2,… из соотношений en=Pn + Qne. Формулы для производящих рядов этих полиномов содержат наиболее важные такие свойства. Эти формулы были получены и имеют вид: 0Pktk=1+t1+t+t2 и 0Qktk=t1+t+t2 ., Let will be an arbitrary finite field of characteristic 2. It’s square extension will be considered as an algebra with basiс elements 1 and e over the field . Here is considered as the unit element of the algebra, and satisfies the relation: . An element maybe arbitrary from the field , but it is not satisfying to the condition for some element from . Let us denote the order of basis element . Then the main result of the paper can be formulated as: The irreducible polynomial divides the polynomial if and only the order if divides a natural . The similar results for arbitrary elements of field follow from main theorem. The proof of main result based on the properties of the recurrence relations between the polynomials and , definite for all by the relations + . The formulas for the generating series of these polynomials contain the most important such properties. The formulas were obtained and we have: , ., Международный научный журнал "Современные информационные технологии и ИТ-образование", Выпуск 2 2020, Pages 314-320
- Published
- 2020
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14. DIFFERENTIATION OF POLYNOMIALS IN SEVERAL VARIABLES OVER GALOIS FIELDS OF FUZZY CARDINALITY AND APPLICATIONS TO REED-MULLER CODES
- Author
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V. M. Deundyak and N. S. Mogilevskaya
- Subjects
Polynomial ,Source data ,polynomial derivatives ,Basis (linear algebra) ,decoding ,Galois theory ,Reed–Muller code ,Coding theory ,Algebra ,Finite field ,reed-muller codes ,Management of Technology and Innovation ,Linear algebra ,galois fields ,TA401-492 ,partitioned data transmission ,differentiation of polynomials ,polynomials in several variables ,Materials of engineering and construction. Mechanics of materials ,Mathematics ,Computer Science::Information Theory - Abstract
Introduction. Polynomials in several variables over Galois fields provide the basis for the Reed-Muller coding theory, and are also used in a number of cryptographic problems. The properties of such polynomials specified over the derived Galois fields of fuzzy cardinality are studied. For the results obtained, two real-world applications are proposed: partitioning scheme and Reed-Muller code decoder.Materials and Methods. Using linear algebra, theory of Galois fields, and general theory of polynomials in several variables, we have obtained results related to the differentiation and integration of polynomials in several variables over Galois fields of fuzzy cardinality. An analog of the differentiation operator is constructed and studied for vectors.Research Results. On the basis of the obtained results on the differentiation and integration of polynomials, a new decoder for Reed-Muller codes of the second order is given, and a scheme for organizing the partitioned transfer of confidential data is proposed. This is a communication system in which the source data on the sender is divided into several parts and, independently of one another, transmitted through different communication channels, and then, on the receiver, the initial data is restored of the parts retrieved. The proposed scheme feature is that it enables to protect data, both from the nonlegitimate access, and from unintentional errors; herewith, one and the same mathematical apparatus is used in both cases. The developed decoder for the second-order Reed-Muller codes prescribed over the derived odd Galois field may have a constraint to the recoverable error level; however, its use is advisable for a number of the communication channels.Discussion and Conclusions. The proposed practical applications of the results obtained are useful for the organization of reliable communication systems. In future, it is planned to study the restoration process of the original polynomial by its derivatives, in case of their partial distortion, and the development of appropriate applications.
- Published
- 2018
15. Investigation of the Practical Possibility of Solving Problems on Generalized Cellular Automata Associated with Cryptanalysis by Mean Algebraic Methods
- Author
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P. G. Klyucharev
- Subjects
Discrete mathematics ,algebraic cryptanalysis ,Hash function ,System of polynomial equations ,Cellular automaton ,law.invention ,Algebra ,Gröbner basis ,Finite field ,generalized cellular automata ,law ,Cryptographic hash function ,QA1-939 ,groebner basis ,Cryptanalysis ,Mathematics ,Block cipher ,Computer Science::Cryptography and Security - Abstract
A number of previous author’s papers proposed methods for constructing various cryptographic algorithms, including block ciphers and cryptographic hash functions, based on generalized cellular automata. This one is aimed at studying a possibility to use the algebraic cryptanalysis methods related to the construction of Grobner bases for the generalized cellular automata to be applied in cryptography, i.e. this paper studies the possibility for using algebraic cryptanalysis methods to solve the problems of inversion of a generalized cellular automaton and recovering the key of such an automaton. If the cryptographic algorithm is represented as a system of polynomial equations over a certain finite field, then its breach is reduced to solving this system with respect to the key. Although the problem of solving a system of polynomial equations in a finite field is NP-difficult in the general case, the solution of a particular system can have low computational cost. Cryptanalysis based on the construction of a system of polynomial equations that links plain text, cipher-text and key, and its solution by algebraic methods, is usually called algebraic cryptanalysis. Among the main methods to solve systems of polynomial equations are those to construct Grobner bases. Cryptanalysis of ciphers and hash functions based on generalized cellular automata can be reduced to various problems. We will consider two such problems: the problem of inversion of a generalized cellular automaton, which, in case we know the values of the cells after k iterations, enables us to find the initial values. And the task of recovering the key, which is to find the initial values of the remaining cells, using the cell values after k steps and the initial values of a part of the cells. A computational experiment was carried out to solve the two problems above stated in order to determine the maximum size of a generalized cellular automaton for which the solution of these problems was possible. Using a Python language program, random 6-regular Ramanujan graphs with the appropriate number of vertices were generated. For each graph, was generated a system of equations that describes the k steps of the corresponding generalized cellular automaton. For the systems obtained, the Grebner bases were constructed using the Fouger algorithm F4, the Magma system v2.21-5, and the Polybori 0.8.3 library. The experiments were carried out both for the inversion task and for the key recovery task. We used a 16-core 16 GB RAM Intel Xeon E5-2690 computer, OS Linux. The article presents the results of experiments that confirm that the algebraic cryptanalysis of block ciphers and hash functions based on generalized cellular automata with the number of cells used in practice (of the order of several hundred or more) available tool based on the use of Grobner bases, is impossible.
- Published
- 2017
16. Письмо в редакцию
- Subjects
skew field ,минимально полное кольцо ,matrix ring ,кольцо матриц ,конечное поле ,Associative ring ,minimal complete ring ,finite field ,Ассоциативное кольцо ,тело - Abstract
Сообщается об одном ошибочном утверждении нашей статьи О минимально полных ассоциативных кольцах., We report on one erroneous statement of our article On minimally complete associative rings., №2(24) (2019)
- Published
- 2019
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17. Вычисление минимальной степени многочлена над конечным полем для векторного булевого отображения, заданного полиномами Жегалкина
- Author
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Belov, S.A.
- Subjects
булевы функции ,Boolean Function ,SAT-Solvers ,Finite Field ,интерполяционный криптоанализ ,SAT-решатели ,конечное поле ,Interpolation Cryptanalysis ,Trace Form ,трейс-форма - Abstract
Рассматриваются векторные отображения над множеством из нуля и единицы, заданные множеством булевых функций. Булевы функции, входящие в отображение, в свою очередь, задаются полиномами Жегалкина. Зафиксировав правило, по которому двоичным векторам ставятся в соответствие элементы конечного поля характеристики два, получаем взаимно-однозначное соответствие между отображениями векторного пространства в себя и функциями над конечным полем. Конечное поле рассматривается как кольцо многочленов с операциями сложения и умножения по модулю выбранного неприводимого многочлена. Известно, что любую функцию над конечным полем можно записать в виде полинома. При этом для различных неприводимых многочленов полиномы над конечным полем, соответствующие заданному векторному отображению, в общем случае, могут быть различными и иметь различные степени. Рассматривается задача поиска такого неприводимого многочлена, чтобы степень полинома над конечным полем была минимальной, при условии, что соответствие между двоичными векторами и элементами конечного поля задаётся использованием полиномиального базиса конечного поля. Для решения задачи булевы функции представляются своими трейс-формами. Из этого представления коэффициенты полинома над конечным полем выражаются через элементы дуального базиса конечного поля. Затем элементы дуального базиса выражаются через полиномиальный базис конечного поля и коэффициенты неприводимого многочлена. Таким образом, коэффициент полинома над конечным полем выражаются в полиномиальном базисе конечного поля. Полученные уравнения сводятся к системе булевых уравнений для коэффициентов неприводимого многочлена. Для решения системы булевых уравнений используется SAT-решатель. Приведены оценки сложности получения указанной системы булевых уравнений., We consider vector mappings over the set of 0 and 1 given by the set of Boolean functions. Boolean functions included in the map are given in ANF. Having fixed the rule according to which the binary vectors are associated with the elements of a finite field of characteristic two, we obtain a one-to-one correspondence between the mappings of the vector space into itself and the functions over the finite field. The finite field is considered as a ring of polynomials with the operations of addition and multiplication modulo the selected irreducible polynomial. It is known that any function over a finite field can be written as a polynomial. Moreover, for various irreducible polynomials, the polynomials over a finite field, corresponding to a given vector map, may in general be different and have different properties. We consider the problem of finding an irreducible polynomial such that the degree of a polynomial over a finite field is minimal, provided that the correspondence between binary vectors and elements of a finite field is given by using a polynomial basis of a finite field. We present an algorithm to solve this problem. Firstly we rewrite Boolean functions in trace form and calculate expressions for finite field polynomial coefficients. Then we calculate elements of dual basis as an expression of polynomial basis. Using them we obtain system pf Boolean equations. Finally we solve system of Boolean equations by SAT-solver and filter reducible polynomials. We estimate of the complexity of obtaining the specified system of Boolean equations is bitwise operations., №1 (2019)
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- 2019
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18. Some properties of the output sequences of combined generator over finite fields
- Author
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Aulet R. Rodriguez
- Subjects
Physics ,Generator (computer programming) ,Finite field ,конечные поля ,сбалансированные функции ,комбинированные генераторы ,корреляционно-иммунные функции ,Topology - Abstract
The sequences are an important part of the cryptography and analysis of their properties is of great interest. In this paper, the following characteristics of combined generator are analyzed: period of output sequences and the distribution of elements in the output sequences over finite field.
- Published
- 2019
19. Halving of twisted Edwards curve points and its application in cryptography
- Subjects
скінчене поле ,алгебраїчна крива ,група точок еліптичної кривої ,подільність точки кривої навпіл ,конечное поле ,алгебраическая кривая ,группа точек эллиптической кривой ,делимость точки кривой пополам ,УДК 681.3 ,finite field ,elliptic curve ,Edwards curve ,order of a curve ,algebraic curve ,group of points of an elliptic curve ,order of a point ,torsion curves - Abstract
Большинство криптосистем современной криптографии естественным образом можно реализовать на эллиптических кривых. Мы рассматриваем алгебраические кривые в форме Эдвардса над простым полем, Fp, которые сейчас являются одними из наиболее перспективных носителей групп, используемых в асимметричных криптосистемах. Показано, что проективная кривая Эдвардса не является эллиптической. Исследовано некоторые интересные свойства группы точек этих кривых. Найдено род скрученной кривой Эдвардса и ее особые точки. Показано возможность построения генератора случайных крипто стойких последовательностей на этой кривой. Предложена нормализация скрученной кривой Эдвардса. Исследованы условия делимости на два элемента из группы точек скрученной кривой Эдвардса над полем . Целью роботы есть поиск критерия делимости точки кривой напополам над полем и анализ свойств скрученной кривой Эдвардса необходимых для построения генератора псевдослучайных крипто стойких последовательностей., Більшість криптосистем сучасної криптографії природним чином можна реалізувати на еліптичні криві. Ми розглядаємо алгебраїчні криві Едвардса над скінченним полем , які на даний час є одним з найбільш перспективних носіїв множин точок, що використовують для швидких групових операцій, які наявні в асиметричних криптосистемах, зокрема для побудови випадкових криптостійких послідовностей. Показано, що проективна крива не є еліптичною. Досліджено умови існування подільності навпіл елемента з групи точок скрученої кривої Едвардса , що є важливим в алгоритмах. Знайдено рід скрученої кривої Едвардса. Метою роботи є пошук критерію подільності точки кривої навпіл над полем і аналіз властивостей скрученої кривої Едвардса необхідних для побудови генератора псевдовипадкових криптостійких послідовностей і побудова односторонньої функції для нього., Most cryptosystems of modern cryptography can be naturally transformed into elliptic curves. We review Edwards algebraic curves over a finite field, which at the present time is one of the most promising carriers of sets of points that are used for fast group operations. These are found in asymmetric cryptosystems. In particular, for constructing random crypto-stable sequences. It is shown that the projective curve is not elliptic.The conditions of the existence of divisibility in half an element from the group of points of the twisted curve of Edwards , which is important in algorithms, are investigated. The type of twisted curve Edwards is found. The purpose of the work is to find the criterion of the divisibility of the point of the curve in half over the field and to analyze the properties of the twisted curve of Edwards necessary for constructing a generator of pseudo-random crypto-stable sequences and constructing a one-way function for it.
- Published
- 2018
20. О плотности полугрупп натуральных чисел
- Subjects
делимость ,плотность множества ,divisibility ,density sets ,finite field - Abstract
Изучается плотность полугрупп на коротких интервалах., We study the distribution of semigroups of integers on small intervals., №1 (2018)
- Published
- 2018
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