8 papers
Explicit cost analysis of Toom-4 multiplication for incomplete NTT in lattice-based cryptography
Sakura Oku, Momonari Kudo
Polynomial multiplication is fundamental in lattice-based cryptography. While the Number Theoretic Transform (NTT) enables fast multiplication, it imposes constraints on the modulu…
On superspecial hyperelliptic curves of genus 5 whose automorphism groups contain
Ryo Ohashi, Momonari Kudo
While the numbers of superspecial curves of genus at most 3 are well understood, and several computational approaches have been developed to count superspecial curves of genus 4 wi…
Listing superspecial curves of genus three using Richelot isogeny graphs
Ryo Ohashi, Hiroshi Onuki, Momonari Kudo +2
In algebraic geometry, superspecial curves are important research objects. While the number of superspecial genus-3 curves in characteristic is known, the number of hyperellipt…
Generalization of semi-regular sequences: Maximal Gröbner basis degree, variants of genericness, and related conjectures
Momonari Kudo, Kazuhiro Yokoyama
Nowadays, the notion of semi-regular sequences, originally proposed by Fröberg, becomes very important not only in Mathematics, but also in Information Science, in particular Cryp…
The solving degrees for computing Gröbner bases of affine semi-regular polynomial sequences
Momonari Kudo, Kazuhiro Yokoyama
In this paper, we study the solving degrees for affine semi-regular sequences and their homogenized sequences. Some of our results are considered to give mathematically rigorous pr…
Some explicit arithmetic on curves of genus three and their applications
Tomoki Moriya, Momonari Kudo
A Richelot isogeny between Jacobian varieties is an isogeny whose kernel is included in the -torsion subgroup of the domain. A Richelot isogeny whose codomain is the product of…