Paper 2021/372 Original: eprint.iacr.org/2021/372 ↗

Explicit connections between supersingular isogeny graphs and Bruhat–Tits trees

Laia Amorós
Annamaria Iezzi
Kristin Lauter
Chloe Martindale
Jana Sotáková
Abstract

We give an exposition of supersingular isogeny graphs, quaternion ideal graphs and Bruhat–Tits trees, and of their connections. Bruhat–Tits trees are combinatorial objects whose vertices and edges have a very simple representation as two-by-two matrices, which, as we show, is useful for understanding certain aspects of the corresponding elliptic curves and isogenies. Moreover Bruhat–Tits trees can be given an orientation and a notion of depth that we translate into the setting of supersingular isogeny graphs. We give some suggestions towards using Bruhat–Tits trees as a tool for cryptanalysis of certain cryptosystems based on supersingular isogeny graphs.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint.
History
2021-03-22: last updated
2021-03-22: published
Short URL
https://ia.cr/2021/372
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2021/372,
      author = {Laia Amorós and Annamaria Iezzi and Kristin Lauter and Chloe Martindale and Jana Sotáková},
      title = {Explicit connections between supersingular isogeny graphs and Bruhat–Tits trees},
      howpublished = {Cryptology {ePrint} Archive, Paper 2021/372},
      year = {2021},
      url = {https://eprint.iacr.org/2021/372}
}
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