Paper 2024/1776
An efficient collision attack on Castryck-Decru-Smith’s hash function
Abstract
In 2020, Castryck-Decru-Smith constructed a hash function using the (2,2)-isogeny graph of superspecial principally polarized abelian surfaces. In their construction, the initial surface was chosen from vertices quite "close" to the square of a supersingular elliptic curve with a known endomorphism ring. In this paper, we propose an algorithm for recovering a collision on their hash function. Under some heuristic assumptions, the time complexity and space complexity of our algorithm are estimated to be
Metadata
- Available format(s)
-
PDF
- Category
- Attacks and cryptanalysis
- Publication info
- Published elsewhere. Minor revision. PQCrypto 2025
- Keywords
- Hash functionIsogeny-based cryptographySuperspecial abelian surfaceKani's lemma
- Contact author(s)
-
ryo-ohashi @ g ecc u-tokyo ac jp
hiroshi-onuki @ g ecc u-tokyo ac jp - History
- 2025-03-13: revised
- 2024-10-31: received
- See all versions
- Short URL
- https://ia.cr/2024/1776
- License
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CC BY
BibTeX
@misc{cryptoeprint:2024/1776, author = {Ryo Ohashi and Hiroshi Onuki}, title = {An efficient collision attack on Castryck-Decru-Smith’s hash function}, howpublished = {Cryptology {ePrint} Archive, Paper 2024/1776}, year = {2024}, url = {https://eprint.iacr.org/2024/1776} }