13 papers
Comparative monotonicity of linear codes by Hermitian and symplectic hull dimensions
Keita Ishizuka
Extending recent work on the Euclidean hull, we derive closed-form ratio decompositions for the number of linear codes with prescribed Hermitian and symplectic hull dimension. The…
The Closure of LCD-to-GI Reductions via Generalized Inner Products
Keita Ishizuka
The Permutation Equivalence Problem (PEP) for linear codes is a fundamental problem in coding theory and cryptography. A recent reduction shows that PEP for Linear Complementary Du…
Binary Caps and LCD Codes with Large Dimensions
Keita Ishizuka, Yuhi Kamio
We establish a connection between linear complementary dual (LCD) codes and caps in projective space. Using this framework and the structure theory of maximal caps, we derive nonex…
Almost All Vectorial Functions Have Trivial Extended-Affine Stabilizers
Keita Ishizuka
We prove that asymptotically almost all vectorial functions over finite fields have trivial extended-affine stabilizers. As a consequence, the number of EA-equivalence classes is a…
Constructions of self-orthogonal and LCD subspace codes
Dean Crnković, Keita Ishizuka, Hadi Kharaghani +2
Recently, the notions of self-orthogonal subspace codes and LCD subspace codes were introduced, and LCD subspace codes obtained from mutually unbiased weighing matrices were studie…
Binary LCD Codes and Their Graph Representations
Keita Ishizuka
We give a complete characterization of simple graphs whose adjacency matrices generate binary linear complementary dual (LCD) codes. In particular, we completely characterize a dis…