Uniform samplers for linear codes with fixed hull dimensions

Uniform Sampling of Linear Codes with Prescribed Hull Dimension

Information Theory

Summary

The paper addresses how to randomly generate linear error-correcting codes that have a specific type of structure called the hull, which is important for certain inner products used in coding theory. The authors provide exact methods to sample these codes uniformly, meaning every code with the desired hull property has an equal chance of being chosen. Their approach works efficiently over various kinds of finite fields and inner product types. This is the first such method available in most cases except one special case already studied.

What this means in practice

Authors

Keita Ishizuka

Abstract

We give exactly uniform samplers for linear codes with prescribed hull dimension, for the Euclidean, Hermitian, and symplectic inner products and over finite fields of every characteristic. Except for the Euclidean form over fields of odd characteristic, these are the first uniform samplers for arbitrary prescribed hull dimension. Each sample costs an expected $O(k^2 N + k \log q)$ field operations for codes of dimension $k$ in a space of dimension $N$ over $\mathbb{F}_q$ or $\mathbb{F}_{q^2}$.