Paper 2025/429
Enhanced CKKS Bootstrapping with Generalized Polynomial Composites Approximation
, Seoul National University, Chung-Ang University, Seoul National UniversityAbstract
Bootstrapping in approximate homomorphic encryption involves evaluating the modular reduction function. Traditional methods decompose the modular reduction function into three components: scaled cosine, double-angle formula, and inverse sine. While these approaches offer a strong trade-off between computational cost and level consumption, they lack flexibility in parameterization. In this work, we propose a new method to decompose the modular reduction function with improved parameterization, generalizing prior trigonometric approaches. Numerical experiments demonstrate that our method achieves near-optimal approximation errors. Additionally, we introduce a technique that integrates the rescaling operation into matrix operations during bootstrapping, further reducing computational overhead.
Metadata
- Available format(s)
-
PDF
- Category
- Public-key cryptography
- Publication info
- Published elsewhere. AsiaCCS '25
- Keywords
- Homomorphic EncryptionBootstrappingCKKS (Cheon-Kim-Kim-Song)
- Contact author(s)
-
minsh @ snu ac kr
jwlee2815 @ cau ac kr
y song @ snu ac kr - History
- 2025-03-06: approved
- 2025-03-06: received
- See all versions
- Short URL
- https://ia.cr/2025/429
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2025/429,
author = {Seonhong Min and Joon-woo Lee and Yongsoo Song},
title = {Enhanced {CKKS} Bootstrapping with Generalized Polynomial Composites Approximation},
howpublished = {Cryptology {ePrint} Archive, Paper 2025/429},
year = {2025},
url = {https://eprint.iacr.org/2025/429}
}
