On True Minimum Distances of Goppa Codes
Abstract
Binary Goppa codes are important in coding theory and cryptography. It is well-known that the minimum distance of a binary Goppa code defined by a squarefree polynomial of degree r is at least 2r+1. Though from the classical results of C. J. Moreno, O. Moreno, F. Levy-dit-Vehel and S. Litsyn that the true minimum distances of binary Goppa codes are 2r+1, when the extension field degree m is larger than (rβ1)4r. There have only very few families of binary Goppa codes with determined true minimum distances. In this paper, we give necessary and sufficient conditions for binary Goppa codes such that their minimum distances are 2r+1 and 2r+2. Infinitely many infinite families of binary Goppa codes with minimum distance 2r+1 are given. In particular, we construct such codes for every Goppa degree r in the range 2hβ1<r<2h over π½22h. For every 2β€ rβ€β2m/3β, we also obtain at least 2mβ3r+1 distinct monic squarefree Goppa polynomials of degree r over π½2m, such that their related binary Goppa codes have minimum distance 2r+1. We extend a criterion for q-ary Goppa codes to split auxiliary polynomials and obtain some infinite families of q-ary Goppa codes attaining their designed distances r+1. We also construct infinite families of binary Goppa codes with minimum distance exactly 2r+2.
Related
- Plotkin-optimal pure quantum LRCs with large minimum distances from NMDS codes
- Convolutional Codes from Cyclic Codes with Guaranteed Free and Local Minimum Distances
- Minimum distances of primitive narrow-sense BCH codes via good zero-sets
- Generalized Skew Multivariate Goppa Codes
- Equality and iso-duality of Generalized Geometric Goppa codes
BibTeX
@misc{chen2026true,
title = {{On True Minimum Distances of Goppa Codes}},
author = {Yaqi Chen and Hao Chen and Chao Liu and Huimin Lao},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.26450},
eprint = {2610.26450},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.26450},
}
RIS
TY - UNPB
TI - On True Minimum Distances of Goppa Codes
AU - Yaqi Chen
AU - Hao Chen
AU - Chao Liu
AU - Huimin Lao
PY - 2026
DA - 2026/10/19
PB - arXiv
DO - 10.48550/arxiv.2610.26450
UR - https://arxiv.org/abs/2610.26450
AB - Binary Goppa codes are important in coding theory and cryptography. It is well-known that the minimum distance of a binary Goppa code defined by a squarefree polynomial of degree r is at least 2r+1. Though from the classical results of C. J. Moreno, O. Moreno, F. Levy-dit-Vehel and S. Litsyn that the true minimum distances of binary Goppa codes are 2r+1, when the extension field degree m is larger than (rβ1)^4r. There have only very few families of binary Goppa codes with determined true minimum distances. In this paper, we give necessary and sufficient conditions for binary Goppa codes such that their minimum distances are 2r+1 and 2r+2. Infinitely many infinite families of binary Goppa codes with minimum distance 2r+1 are given. In particular, we construct such codes for every Goppa degree r in the range 2^hβ1<r<2^h over π½_2^2h. For every 2β€ rβ€β2^m/3β, we also obtain at least 2^mβ3r+1 distinct monic squarefree Goppa polynomials of degree r over π½_2^m, such that their related binary Goppa codes have minimum distance 2r+1. We extend a criterion for q-ary Goppa codes to split auxiliary polynomials and obtain some infinite families of q-ary Goppa codes attaining their designed distances r+1. We also construct infinite families of binary Goppa codes with minimum distance exactly 2r+2.
ER -