Bootstrapping GBFV with CKKS

Jaehyung Kim

Paper 2025/888

Bootstrapping GBFV with CKKS

Jaehyung Kim

, Stanford University

Abstract

The Generalized BFV [Geelen and Vercauteren; Eurocrypt'25] is an efficient fully homomorphic encryption scheme that supports integer computations over large cyclotomic moduli. However, the only known bootstrapping approach cannot support large precision as it uses BFV linear transformation as a subroutine. In this work, we introduce a GBFV bootstrapping that relies on CKKS bootstrapping as in the BFV bootstrapping from CKKS [Kim et al.; CCS'24]. The new bootstrapping can handle arbitrary precision, notably bootstrapping the CLPX scheme [Chen et al.; CT-RSA'18] for the first time, bootstrapping up to $500,000$ bits of plaintext modulus in less than $20$ seconds. In addition, we introduce conversions between GBFV and CKKS and discuss its impact.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Preprint.
Keywords: GBFV Bootstrapping CLPX CKKS
Contact author(s): jaehk @ stanford edu
History: 2025-05-19: approved; 2025-05-19: received; See all versions
Short URL: https://ia.cr/2025/888
License: CC BY

BibTeX

@misc{cryptoeprint:2025/888,
      author = {Jaehyung Kim},
      title = {Bootstrapping {GBFV} with {CKKS}},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/888},
      year = {2025},
      url = {https://eprint.iacr.org/2025/888}
}