Paper 2023/1223
Improved Circuit Synthesis with Multi-Value Bootstrapping for FHEW-like Schemes
Abstract
In recent years, the research community has made great progress in improving techniques for privacy-preserving computation, such as fully homomorphic encryption (FHE). Despite the progress, there remain open challenges, mainly in performance and usability, to further advance the adoption of these technologies. This work provides multiple contributions that improve the current state-of-the-art in both areas. More specifically, we significantly simplify the multi-value bootstrapping by Carpov, Izabachène, and Mollimard [CIM19] for Boolean-based FHE schemes such as FHEW or TFHE, making the concept usable in practice. Based on our simplifications, we implement an easy-to-use interface for multi-value bootstrapping in the open-source library FHE-Deck [fhe23], derive new parameter sets for multi-bit encryptions with state-of-the-art security, and build a toolset that translates high-level code to multi-bit operations on encrypted data using circuit synthesis. We propose and integrate the first non-trivial FHE-specific optimizations for privacy-preserving circuit synthesis: look-up table (LUT) grouping and adder substitution. Using LUT grouping, we reduce the number of bootstrapping operations by almost 40% on average, while for adder substitution, we reduce the number of required bootstrappings by up to 85% for certain use cases. Overall, the execution time is up to 4.2x faster with all optimizations enabled compared to previous state-of-the-art circuit synthesis.
Metadata
- Available format(s)
-
PDF
- Category
- Implementation
- Publication info
- Published by the IACR in TCHES 2024
- DOI
- https://doi.org/10.46586/tches.v2024.i4.633-656
- Keywords
- fully homomorphic encryptionFHEWTFHEcircuit synthesis
- Contact author(s)
-
johannes mono @ rub de
kamil kluczniak @ cispa de
tim gueneysu @ rub de - History
- 2024-09-07: last of 2 revisions
- 2023-08-11: received
- See all versions
- Short URL
- https://ia.cr/2023/1223
- License
-
CC0
BibTeX
@misc{cryptoeprint:2023/1223,
author = {Johannes Mono and Kamil Kluczniak and Tim Güneysu},
title = {Improved Circuit Synthesis with Multi-Value Bootstrapping for {FHEW}-like Schemes},
howpublished = {Cryptology {ePrint} Archive, Paper 2023/1223},
year = {2023},
doi = {https://doi.org/10.46586/tches.v2024.i4.633-656},
url = {https://eprint.iacr.org/2023/1223}
}