Paper 2026/2677

Smoothness of Shortest Isogenies to Frobenius Conjugatess

Yi Ouyang, University of Science and Technology of China, Hefei National Laboratory
Wei Wei, University of Science and Technology of China
Zheng Xu, Hefei National Laboratory
Abstract

Let \(E\) be chosen uniformly from the geometric isomorphism classes of supersingular elliptic curves over \(\overline{\mathbb{F}}_p\) and \(\delta_E\) be the minimum degree of isogenies from \(E\) to its Frobenius conjugate \(E^{(p)}\). We establish bounds for the smoothness probability of $\delta_E$ and hence affirm Wesolowski's \(p^{1/3+o(1)}\) attack on the supersingular endomorphism ring problem is unconditional. We also establish a uniform asymptotic formula, with a main term expressed in terms of Dirichlet \(L\)-values, for the probability that a connection isogeny of degree $n$ exists between $E$ and $E^{(p)}$.

Metadata
Available format(s)
PDF
Category
Attacks and cryptanalysis
Publication info
Preprint.
Keywords
Supersingular elliptic curvesleast isgeny degreesmooth numberBrandt operatorWesolowski’s p1/3-attack.
Contact author(s)
yiouyang @ ustc edu cn
veivei @ mail ustc edu cn
xuzheng1 @ mail ustc edu cn
History
2026-10-31: approved
2026-10-29: received
See all versions
Short URL
https://ia.cr/2026/2677
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2026/2677,
      author = {Yi Ouyang and Wei Wei and Zheng Xu},
      title = {Smoothness of Shortest Isogenies to Frobenius Conjugatess},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/2677},
      year = {2026},
      url = {https://eprint.iacr.org/2026/2677}
}
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