New Quantum and LCD Codes over Finite Fields of Even Characteristic

For an integer m ≥ 1, we study cyclic codes of length l over a commutative non-chain ring F2m + uF2m , where u2 = u . With a new Gray map and Euclidean dual-containing cyclic codes, we provide many new and superior codes to the best-known quantum error-correcting codes. Also, we characterise LCD codes of length l with respect to their generator polynomials and prove that F2m − image of an LCD code of length l is an LCD code of length 2l . Finally, we provide several optimal LCD codes from the Gray images of LCD codes over F2m + uF2m .

A NOTE ON k-GALOIS LCD CODES OVER THE RING

We study the k-Galois linear complementary dual (LCD) codes over the finite chain ring $R=\mathbb {F}_q+u\mathbb {F}_q$ with $u^2=0$ , where $q=p^e$ and p is a prime number. We give a sufficient condition on the generator matrix for the existence of k-Galois LCD codes over R. Finally, we show that a linear code over R (for $k=0, q> 3$ ) is equivalent to a Euclidean LCD code, and a linear code over R (for $0<k<e$ , $(p^{e-k}+1)\mid (p^e-1)$ and ${(p^e-1)}/{(p^{e-k}+1)}>1$ ) is equivalent to a k-Galois LCD code.

On the Construction of Binary Optimal LCD Codes with Short Length

A [Formula: see text]-ary linear code [Formula: see text] is called a linear complementary dual (LCD) code if it meets its dual trivially. Binary LCD codes play a significant role for their advantage of low complexity for implementations against side-channel attacks and fault injection attacks. In this paper, the problem of finding LCD codes over the binary field is discussed. Many new codes and new bounds are presented, as well as a table of optimal LCD codes (or upper and lower bounds on such codes) of length up to 30 bits.