Linear Complementary Dual Codes and Linear Complementary Pairs of AG Codes in Function Fields

Linear complementary dual (LCD) codes is a class of linear codes introduced by Massey in 1964. LCD codes have been extensively studied in literature recently. In addition to their applications in data storage, communications systems, and consumer electronics, LCD codes have been employed in cryptography. More specifically, it has been shown that LCD codes can also help improve the security of the information processed by sensitive devices, especially against so-called side-channel attacks (SCA) and fault non-invasive attacks. In this paper, we are interested in the construction of particular algebraic geometry (AG) LCD codes which could be good candidates to be resistant against SCA. We firstly provide a construction scheme for obtaining LCD codes from elliptic curves. Then, some explicit LCD codes from elliptic curve are presented. MDS codes are of the most importance in coding theory due to their theoretical significance and practical interests. In this paper, all the constructed LCD codes from elliptic curves are MDS or almost MDS. Some infinite classes of LCD codes from elliptic curves are optimal due to the Griesmer bound. Finally, we introduce a construction mechanism for obtaining LCD codes from any algebraic curve and derive some explicit LCD codes from hyperelliptic curves and Hermitian curves.

Linear complementary pairs (LCPs) of codes play an important role in armoring implementations against sidechannel attacks and fault injection attacks. One of the most common ways to construct LCP of codes is to use Euclidean linear complementary dual (LCD) codes. In this paper, we first introduce the concept of linear codes with o complementary dual (σ-LCD), which includes known Euclidean LCD codes, Hermitian LCD codes, and Galois LCD codes. Like Euclidean LCD codes, σ-LCD codes can also be used to construct LCP of codes. We show that for q 2, all q-ary linear codes are σ-LCD, and for every binary linear code C, the code {0} × C is σ-LCD. Furthermore, we study deeply σ-LCD generalized quasi-cyclic (GQC) codes. In particular, we provide the characterizations of σ-LCD GQC codes, self-orthogonal GQC codes, and self-dual GQC codes, respectively. Moreover, we provide the constructions of asymptotically good σ-LCD GQC codes. Finally, we focus on σ-LCD abelian codes and prove that all abelian codes in a semisimple group algebra are σ-LCD. The results derived in this paper extend those on the classical LCD codes and show that σ-LCD codes allow the construction of LCP of codes more easily and with more flexibility.

Further results on Euclidean and Hermitian linear complementary dual codes

Massey introduced a class of linear code which is called linear complementary dual (LCD) codes. It has been known that LCD codes play a significant role in improving the security of the information processed by sensitive device. In this paper, we constructed 166 quaternary Hermitian linear complementary dual codes with small distance, where 154 codes are new constructions. Besides, it includes 145 Hermitian optimal LCD codes and 9 Hermitian near optimal LCD codes.

A linear complementary-dual (LCD) code C is a linear code whose dual code $$C^{\perp }$$ satisfies $$C \cap C^{\perp }=\{0\}$$ . In this work we characterize some classes of LCD q-ary $$(\lambda , l)$$ -quasi-twisted (QT) codes of length $$n=ml$$ with $$(m,q)=1$$ , $$\lambda \in F_{q} \setminus \{0\}$$ and $$\lambda \ne \lambda ^{-1}$$ . We show that every $$(\lambda ,l)$$ -QT code C of length $$n=ml$$ with $$dim(C)<m$$ or $$dim(C^{\perp })<m$$ is an LCD code. A sufficient condition for r-generator QT codes is provided under which they are LCD. We show that every maximal 1-generator $$(\lambda ,l)$$ -QT code of length $$n=ml$$ with $$l>2$$ is either an LCD code or a self-orthogonal code and a sufficient condition for this family of codes is given under which such a code C is LCD. Also it is shown that every maximal 1-generator $$(\lambda ,2)$$ -QT code is LCD. Several good and optimal LCD QT codes are presented.

Cyclic codes over a non-chain ring Re,q and their application to LCD codes

Linear complementary dual (LCD) cyclic codes were referred historically to as reversible cyclic codes, which had applications in data storage. Due to a newly discovered application in cryptography, there has been renewed interest in LCD codes. In particular, it has been shown that binary LCD codes play an important role in implementations against side-channel attacks and fault injection attacks. In this paper, we first present a new characterization of binary LCD codes in terms of their symplectic basis. Using such a characterization,we solve a conjecture proposed by Galvez et al. on the minimum distance of binary LCD codes. Next, we consider the action of the orthogonal group on the set of all LCD codes, determine all possible orbits of this action, derive simple closed formulas of the size of the orbits, and present some asymptotic results of the size of the corresponding orbits. Our results show that almost all binary LCD codes are odd-like codes with odd-like duals, and about half of q-ary LCD codes have orthonormal basis, where q is a power of an odd prime.

Theory of additive complementary dual codes, constructions and computations

We study linear complementary pairs (LCP) of codes $(C, D)$ , where both codes belong to the same algebraic code family. We especially investigate constacyclic and quasi-cyclic LCP of codes. We obtain characterizations for LCP of constacyclic codes and LCP of quasi-cyclic codes. Our result for the constacyclic complementary pairs extends the characterization of linear complementary dual (LCD) cyclic codes given by Yang and Massey. We observe that when $C$ and $D$ are complementary and constacyclic, the codes $C$ and $D^\bot $ are equivalent to each other. Hence, the security parameter $\min (d(C),d(D^\bot))$ for LCP of codes is simply determined by one of the codes in this case. The same holds for a special class of quasi-cyclic codes, namely 2D cyclic codes, but not in general for all quasi-cyclic codes, since we have examples of LCP of double circulant codes not satisfying this conclusion for the security parameter. We present examples of binary LCP of quasi-cyclic codes and obtain several codes with better parameters than known binary LCD codes. Finally, a linear programming bound is obtained for binary LCP of codes and a table of values from this bound is presented in the case $d(C)=d(D^\bot)$ . This extends the linear programming bound for LCD codes.

Linear complementary dual codes have become an interesting sub-family of linear codes over finite fields since they can be practically applied in various fields such as cryptography and quantum error-correction. Recently, properties of complementary dual abelian codes were established in group algebras of arbitrary finite abelian groups. However, the enumeration formulas were given mostly based on number-theoretical characteristic functions. In this article, complementary dual abelian codes determined by some finite abelian groups are revisited. Specifically, the characterization of cyclotomic classes of an abelian group and the enumeration of complementary dual abelian codes are presented, where the group is a finite abelian p-group, a finite abelian 2-group, and a product of a finite abelian p-group and a finite abelian 2-group for some odd prime number p different from the characteristic of the alphabet filed. The enumeration formula for such complementary dual codes is given explicitly in a more precise form without characteristic functions. Some illustrative examples are given as well.

It was shown by Massey that linear complementary dual (LCD) codes are asymptotically good. In 2004, Sendrier proved that LCD codes meet the asymptotic Gilbert–Varshamov (GV) bound. Until now, the GV bound still remains to be the best asymptotical lower bound for LCD codes. In this paper, we show that an algebraic geometry code over a finite field of even characteristic is equivalent to an LCD code and consequently there exists a family of LCD codes that are equivalent to algebraic geometry codes and exceed the asymptotical GV bound.

Locally recoverable (LRC) codes provide a solution to single node failure in distributed storage systems, where it is a very common problem. On the other hand, linear complementary dual (LCD) codes are useful in fault injections attacks on storage systems. In this paper, we establish a connection between LRC codes and LCD codes. We derive some conditions on the construction of cyclic LRC codes so that they are also LCD codes. A lower bound on the minimum distance of such codes is determined. Some examples have been given to explain the construction.

Linear codes with certain special properties have received renewed attention in recent years due to their practical applications. Among them, binary linear complementary dual (LCD) codes play an important role in implementations against side-channel attacks and fault injection attacks. Self-orthogonal codes can be used to construct quantum codes. In this paper, four classes of binary linear codes are constructed via a generic construction which has been intensively investigated in the past decade. Simple characterizations of these linear codes to be LCD or self-orthogonal are presented. Resultantly, infinite families of binary LCD codes and self-orthogonal codes are obtained. Infinite families of binary LCD codes from the duals of these four classes of linear codes are produced. Many LCD codes and self-orthogonal codes obtained in this paper are optimal or almost optimal in the sense that they meet certain bounds on general linear codes. In addition, the weight distributions of two sub-families of the proposed linear codes are established in terms of Krawtchouk polynomials.

The construction of linear codes from functions in finite fields has been widely studied in the literature. There are two generic construction methods: the first and second generic construction methods for generating linear codes from functions over finite fields. In this paper, we first define the augmented code construction of the variation of the second generic construction method and then present new infinite families of four- and five-weight self-orthogonal divisible codes derived from trace functions. Moreover, by using the augmented code construction based on the first generic construction method, we construct new infinite families of three-weight and four-weight self-orthogonal divisible codes from weakly regular plateaued functions. We determine all parameters of the constructed self-orthogonal codes as well as their dual codes over the odd characteristic finite fields. We present Hamming weights and their weight distributions for the constructed self-orthogonal codes. Additionally, we utilise the constructed p-ary self-orthogonal codes to develop p-ary Linear Complementary Dual (LCD) codes and determine the parameters of the obtained LCD codes and their dual codes.

Due to their important applications in theory and practice, linear complementary dual (LCD) codes and self-orthogonal codes have received much attention in the last decade. The objective of this paper is to extend a recent construction of binary LCD codes and self-orthogonal codes to the general $ p $-ary case, where $ p $ is an odd prime. Based on the extended construction, several classes of $ p $-ary linear codes are obtained. The characterizations of these linear codes to be LCD or self-orthogonal are derived. The duals of these linear codes are also studied. It turns out that the proposed linear codes are optimal in many cases in the sense that their parameters meet certain bounds on linear codes. The weight distributions of these linear codes are settled.