Abstract
We introduce SQIsign2D–West, a variant of SQIsign using two-dimensional isogeny representations.
SQIsignHD introduced four- and eight-dimensional isogeny representations to improve signing times and provable security of SQIsign, at the cost of slower verification. It left open the question of leveraging two-dimensional representations, which we solve here by introducing new algorithmic tools. These lead to a “best-of-both-worlds” scheme: our signing times are only 2 to 3 slower than SQIsignHD but 10 to 15 faster than SQIsign, our security proof rigorously reduces to an assumption similar to the one behind SQIsignHD, and our verification times are the fastest among all present variants of SQIsign. Additionally, like SQIsignHD, SQIsign2D–West favourably scales to high levels of security.
Concretely, for NIST level I we achieve signing times of 80 ms and verifying times of 4.5 ms, using optimised arithmetic for the x86_64 architecture. For NIST level V, we achieve 470 ms for signing and 31 ms for verifying.
SQIsignHD introduced four- and eight-dimensional isogeny representations to improve signing times and provable security of SQIsign, at the cost of slower verification. It left open the question of leveraging two-dimensional representations, which we solve here by introducing new algorithmic tools. These lead to a “best-of-both-worlds” scheme: our signing times are only 2 to 3 slower than SQIsignHD but 10 to 15 faster than SQIsign, our security proof rigorously reduces to an assumption similar to the one behind SQIsignHD, and our verification times are the fastest among all present variants of SQIsign. Additionally, like SQIsignHD, SQIsign2D–West favourably scales to high levels of security.
Concretely, for NIST level I we achieve signing times of 80 ms and verifying times of 4.5 ms, using optimised arithmetic for the x86_64 architecture. For NIST level V, we achieve 470 ms for signing and 31 ms for verifying.
| Original language | English |
|---|---|
| Title of host publication | Advances in Cryptology – ASIACRYPT 2024 |
| Subtitle of host publication | 30th International Conference on the Theory and Application of Cryptology and Information Security, Kolkata, India, December 9–13, 2024, Proceedings, Part III |
| Editors | Kai-Min Chung, Yu Sasaki |
| Publisher | Springer, Singapore |
| Pages | 339-370 |
| Number of pages | 32 |
| ISBN (Electronic) | 9789819608911 |
| ISBN (Print) | 9789819608904 |
| DOIs | |
| Publication status | Published - 12 Dec 2024 |
| Event | ASIACRYPT 2024: 30th International Conference on the Theory and Application of Cryptology and Information Security - Kolkata, India Duration: 9 Dec 2024 → 13 Dec 2024 https://asiacrypt.iacr.org/2024/ |
Publication series
| Name | Lecture Notes in Computer Science |
|---|---|
| Publisher | Springer |
| Volume | 15486 |
| ISSN (Print) | 0302-9743 |
| ISSN (Electronic) | 1611-3349 |
Conference
| Conference | ASIACRYPT 2024 |
|---|---|
| Country/Territory | India |
| City | Kolkata |
| Period | 9/12/24 → 13/12/24 |
| Internet address |
Bibliographical note
Publisher Copyright:© 2025 International Association for Cryptologic Research.