Paper 2026/1545

Zero-Knowledge Proofs of Isogeny Diamonds

Leonardo Colò, University of Waterloo
Maher Mamah, University of Waterloo
Youcef Mokrani, University of Waterloo
Bruno Sterner, University of Waterloo
Nicolas Swanson, University of Waterloo
Abstract

Commutative diagrams of isogenies between supersingular elliptic curves, which are called isogeny diamonds, have become fundamental to isogeny-based cryptography for both constructive and cryptanalytic purposes. In parallel, proofs of knowledge of isogenies have been widely studied and have found many applications. In this work, we combine these two directions and introduce zero-knowledge proofs of isogeny diamonds, namely, we prove knowledge of isogenies that form a commutative diagram between four curves. We present four constructions that work in various settings. The first, Windmill-ZKP assumes that the prover knows only two parallel isogenies in the diamond. The second, Cube-ZKP assumes the prover has knowledge of four of specified degree isogenies. Finally, Kube-ZKP and Kani-ZKP prove knowledge of isogeny diamonds whose degree sum is smooth. We also provide proof-of-concept implementations of the proposed constructions and compare their performance. Our results demonstrate the trade-offs between security, efficiency and compactness in these constructions.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Preprint.
Keywords
zero-knowledge proofsisogeny-based cryptographyisogeny diamondsKani's Lemma
Contact author(s)
lcolo @ uwaterloo ca
mmamah @ uwaterloo ca
youcef mokrani @ uwaterloo ca
bsterner @ uwaterloo ca
nswanson @ uwaterloo ca
History
2026-08-03: approved
2026-07-28: received
See all versions
Short URL
https://ia.cr/2026/1545
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2026/1545,
      author = {Leonardo Colò and Maher Mamah and Youcef Mokrani and Bruno Sterner and Nicolas Swanson},
      title = {Zero-Knowledge Proofs of Isogeny Diamonds},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/1545},
      year = {2026},
      url = {https://eprint.iacr.org/2026/1545}
}
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