Divisibility of polynomials over finite fields and combinatorial applications

We define a statistical measure of the typical size of words of low weight in a linear code over a finite field. We prove that the dual toric codes coming from polytopes of degree one are characterized, among all dual toric codes, by being extremal with respect to this measure. We also give a geometric interpretation of the minimum distance of dual toric codes and characterize its extremal values. Finally, we obtain exact formulas for the parameters of both primal and dual toric codes associated to polytopes of degree one.

In this article we introduce a method of constructing binary linear codes and computing their weights by means of Boolean functions arising from mathematical objects called simplicial complexes. Inspired by Adamaszek (Am Math Mon 122:367–370, 2015) we introduce n-variable generating functions associated with simplicial complexes and derive explicit formulae. Applying the construction (Carlet in Finite Field Appl 13:121–135, 2007; Wadayama in Des Codes Cryptogr 23:23–33, 2001) of binary linear codes to Boolean functions arising from simplicial complexes, we obtain a class of optimal linear codes and a class of minimal linear codes.

Finite field multipliers are the basic building blocks in many applications such as cryptography, error-control coding and digital signal processing. The design of efficient dedicated finite field multiplier architectures can lead to dramatic improvement on the overall system performance. For a given multiplier architecture, its hardware complexity, computation time and power consumption are highly dependent on primitive polynomial p(x). Generally, primitive polynomial is selected to optimize application-oriented parameters, such as minimizing decoding error probability in error-control coding. A secondary selection criterion should be to improve the implementation efficiency, i.e., minimizing area and power consumption while meeting the speed requirement. In this paper, the effects of different primitive polynomials on area and power consumption of semi-systolic finite field multipliers are analyzed. It is shown that the hardware complexity and the total number of transitions can be reduced by selecting the primitive polynomials with less Hamming weight. The optimum primitive polynomials for low area and low power semi-systolic multipliers over different finite field GF(2/sup m/) are provided based on the analysis results.

Linear error-correcting codes can be used for constructing secret sharing schemes; however, finding in general the access structures of these secret sharing schemes and, in particular, determining efficient access structures is difficult. Here we investigate the properties of certain algebraic hypersurfaces over finite fields, whose intersection numbers with any hyperplane only takes a few values; these varieties give rise to q-divisible linear codes with at most 5 weights. Furthermore, for q odd, these codes turn out to be minimal and we characterize the access structures of the secret sharing schemes based on their dual codes. Indeed, the secret sharing schemes thus obtained are democratic, that is each participant belongs to the same number of minimal access sets and can easily be described.

Bent functions over the finite fields of an odd characteristic received a lot of attention of late years. In Cesmelioglu et al. (J Comb Theory Ser A 119:420---429, 2012), Cesmelioglu and Meidl (Des Codes Cryptogr 66:231---242, 2013), an efficient method of construction of weakly regular and non-weakly regular bent functions defined over a finite field with odd characteristic is presented. In this paper, we give an adaptation of this method to the ring of integers modulo $$p^m$$pm, where p is an odd prime and m is a positive integer. We emphasize that different results than the results of the finite field case are obtained in every application process. First, we give a method that constructs bent functions using plateaued functions by increasing the dimension. Then, in order to give concrete examples, we compute Walsh spectrum of some specific quadratic functions defined over the ring of integers modulo $$p^m$$pm and apply the construction method on these functions. There are notable differences between the cases when m is odd and even. Also, we explain how to determine weakly regular and non-weakly regular bent functions among the bent functions that are constructed by the method.

Primitive polynomials are important in hardware realizations for error control codes, cryptography, and other signal processing and communication-based designs. These primitive polynomials over a finite field in association with the core concepts of a particular area of study can be easily implemented on hardware. Researchers have used existing databases of primitive polynomials of various degrees in most cases, generated using a software-based logic. However, not much study has been carried out to implement the logic for computation of primitive polynomials on hardware. This paper describes an implementation of a scalable primitive polynomial circuit. The circuit can compute the primitive polynomial of any degree for a finite field and uses shift registers for the said purpose. This scalable circuit is synthesized on ASIC with a 45 nm CMOS process using Synopsys Design Compiler to assess standard cell area and power. The standard cell area and power consumed by the scalable circuit for various degrees of the primitive polynomial are also analyzed in this paper.

Let L be a number field and OL the ring of algebraic integers in L. For apolynomial f with coefficients in OL, the content of f in L is the ideal of OLgenerated by coefficients of f. The polynomial f is primitive in L if the contentof f in L is OL. In 2005, Arturo Magidin and David McKinnon proved the Gauss’ lemma fornumber fields, the product of two primitive polynomials is also primitive, andsome applications following from Gauss’ lemma for number fields. A function field K over a finite field k is a finite separable field extension overk(x) where x is a transcendantal element. In this research, we study Magidin and McKinnon’s work on the function fields.

This paper examines the w w -weight enumerators of weights w w with maximal symmetry over finite chain rings and matrix rings over finite fields. In many cases, including the homogeneous weight, the MacWilliams identities for w w -weight enumerators fail because there exist two linear codes with the same w w -weight enumerator whose dual codes have different w w -weight enumerators.

Over binary filed F2 there are 16 primitive irreducible polynomials of degree 8, and hence one can construct 16 Galois field extensions of order 256. In this paper, we provide a novel technique to design 16 different robust 8 × 8 substitution boxes (S-boxes) over the elements these 16 Galois fields. For the purpose, on these Galois fields we define 16 linear fractional transformations as: z ⟼ (az + b)/(cz + d), where z is any arbitrary element in any of Galois fields and a, b, c, d are fixed elements from any Galois field GF(28). Accordingly for fixed parameters a, b, c, d, we obtained 16 distinct S-boxes. The algebraic strength of the proposed S-boxes is analyzed by Nonlinearity test, Strict Avalanche Criterion (SAC), Linear Approximation Probability (LP), Bit Independent Criterion (BIC), and Differential Approximation Probability (DP). As an application, by the majority logic criterion (MLC), entropy, correlation, contrast, energy and homogeneity of a plain image and its encrypted image through newly proposed S-box are assessed. Further, to fix the rank of proposed S-boxes, a comparison of these analyses is given with AES S-box, APA S-box, Residue Prime S-box, Gray S-box, Xyi S-box, Skipjack S-box and S8 AES S-box.

A large number of techniques are known for constructing orthogonal arrays. This chapter, the first of several describing these techniques, discusses some constructions due to Bush (1952b), Addelman and Kempthorne (1961a), Rao (1946a, 1947, 1949) and Bose and Bush (1952), that have the common theme of using Galois fields and finite geometries. We also describe a number of basic properties of orthogonal arrays, including the important concept of linearity.

This review article discusses linear complementary duals over finite fields as counter-measures to side-channel attacks, faulty injection attacks, hardware trojan horse attacks, etc. We first discuss some security attacks and the need for linear complementary codes. Then introduce the linear complementary dual codes and study their properties. Some constructions and bounds on the linear complementary codes over finite fields are emphasised. Linear complementary dual codes with respect to different inner products such as Hermitian, Galois, Sigma, etc., are considered in our discussion. We end the survey with some comments on codes over rings.

The $\ell$-Galois hull $h_{\ell}(C)$ of an $[n,k]$ linear code $C$ over a finite field $\mathbb{F}_q$ is the intersection of $C$ and $C^{{\bot}_{\ell}}$, where $C^{\bot_{\ell}}$ denotes the $\ell$-Galois dual of $C$ which introduced by Fan and Zhang (2017). The $\ell$- Galois LCD code is a linear code $C$ with $h_{\ell}(C) = 0$. In this paper, we show that the dimension of the $\ell$-Galois hull of a linear code is invariant under permutation equivalence and we provide a method to calculate the dimension of the $\ell$-Galois hull by the generator matrix of the code. Moreover, we obtain that the dimension of the $\ell$-Galois hulls of ternary codes are also invariant under monomial equivalence. %The dimension of $l$-Galois hull of a code is not invariant under monomial equivalence if $q>4$. We show that every $[n,k]$ linear code over $\mathbb F_{q}$ is monomial equivalent to an $\ell$-Galois LCD code for any $q>4$. We conclude that if there exists an $[n,k]$ linear code over $\mathbb F_{q}$ for any $q>4$, then there exists an $\ell$-Galois LCD code with the same parameters for any $0\le \ell\le e-1$, where $q=p^e$ for some prime $p$. As an application, we characterize the $\ell$-Galois hull of matrix product codes over finite fields.

In this paper, we construct an authentication scheme for multi-receivers and multiple messages based on a linear code C. This construction can be regarded as a generalization of the authentication scheme given by Safavi-Naini and Wang [1]. Actually, we notice that the scheme of Safavi-Naini and Wang is constructed with Reed-Solomon codes. The generalization to linear codes has the similar advantages as generalizing Shamir's secret sharing scheme to linear secret sharing sceme based on linear codes [2—6]. For a fixed message base field ${\mathbb F}_q$ , our scheme allows arbitrarily many receivers to check the integrity of their own messages, while the scheme of Safavi-Naini and Wang has a constraint on the number of verifying receivers $V\leqslant q$ . We further introduce access structure in our scheme. Masseya[4] characterized the access structure of linear secret sharing scheme by minimal codewords in the dual code whose first component is 1. We slightly modify the definition of minimal codewords in [4]. Let C be a [V,k] linear code. For any coordinate i ∈ {1,2, i¾? ,V}, a codeword c in C is called minimal respect to i if the codeword c has component 1 at the i-th coordinate and there is no other codeword whose i-th component is 1 with support strictly contained in that of c. Then the security of receiver R i in our authentication scheme is characterized by the minimal codewords respect to i in the dual code $C^\bot$ . Finally, we illustrate our authentication scheme based on the elliptic curve codes, a special class of algebraic geometry codes. We use the group of rational points on the elliptic curve to determine all the malicious groups that can successfully make a substitution attack to any fixed receiver.

This paper studies linear coding (LC) techniques in the setting of computing functions of correlated memoryless sources. Instead of linear mappings over finite fields, we consider using linear mappings over finite rings as encoders. It is shown that generally the region c×R, where c ≥ 1 is a constant and R is the Slepian-Wolf (SW) region, is achievable with LC over ring (LCoR) when the function to compute is the identity function. c = 1 if the ring used is a field. Hence, LCoR could be suboptimal in terms of achieving the best coding rates (the SW region) for computing the identity function. In spite of that, the ring version shows several advantages. It is demonstrated that there exists a function that is neither linear nor can be linearized over any finite field. Thus, LC over field (LCoF) does not apply directly for computing such a function unless the polynomial approach [1], [2] is used. On the contrary, such a function is linear over some ring. Using LCoR, an achievable region containing the SW region can be obtained for computing this function. In addition, the alphabet sizes of the encoders are strictly smaller than using LCoF. More interestingly, LCoF is not useful if some special requirement is imposed.

Cryptographically strong functions used as S-boxes in block cyphers are fundamental for the cypher’s security. Their representation as lookup tables is possible for functions of small dimension. For larger dimensions, this is infeasible, especially if resources are limited. An alternative is representing the function as a polynomial over a finite field, and constructing a circuit evaluating this polynomial. We study how the choice of primitive polynomial affects the efficiency of hardware implementations. We take Dillon’s permutation on 6 bits (the only known permutation in even dimension from the cryptographically optimal Almost Perfect Nonlinear functions) as a relevant example, and present hardware architectures, polynomial representations and hardware theoretical complexities for all primitive polynomials of degree six. To compare the efficiency, we report on results obtained from FPGA (Field Programmable Gate Array) implementations. To the best of our knowledge, no similar study has been given in the literature. We observe that using the primitive trinomial y6+y+1 reduces the number of 2-input XOR gates up to 11.7% and the number of XOR gates × Delay metrics up to 13.2% with respect to the worst-case implementation. Therefore, the choice of primitive polynomial can profoundly impact the efficiency of such an implementation, and should be carefully considered.