Paper 2025/077
On Multi-Key FuncCPA Secure Encryption Schemes
Abstract
The notion of funcCPA security for homomorphic encryption schemes was introduced by Akavia \textit{et~al.}\ (TCC 2022). Whereas it aims to capture the bootstrapping technique in homomorphic encryption schemes, Dodis \textit{et~al.}\ (TCC 2023) pointed out that funcCPA security can also be applied to non-homomorphic public-key encryption schemes (PKE). As an example, they presented a use case for privacy-preserving outsourced computation without homomorphic computation. It should be noted that prior work on funcCPA security, including the use case presented by Dodis \textit{et~al.}, considered only the single-key setting. However, in recent years, multi-party collaboration in outsourced computation has garnered significant attention, making it desirable for funcCPA security to support the multi-key setting. Therefore, in this work, we introduce a new notion of security called Multi-Key funcCPA (MKfunc) to address this need, and show that if a PKE scheme is KDM-secure, then it is also MKfuncCPA secure. Furthermore, we show that similar discussions can be applied to symmetric-key encryption.
Metadata
- Available format(s)
-
PDF
- Category
- Foundations
- Publication info
- Published elsewhere. 2024 1st International Conference On Cryptography And Information Security (VCRIS)
- DOI
- 10.1109/VCRIS63677.2024.10813389
- Keywords
- cryptographypublic-key encryption schemefuncCPA
- Contact author(s)
- yamashita @ ist osaka-u ac jp
- History
- 2025-01-18: approved
- 2025-01-17: received
- See all versions
- Short URL
- https://ia.cr/2025/077
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2025/077,
author = {Eri Nakajima and Keisuke Hara and Kyosuke Yamashita},
title = {On Multi-Key {FuncCPA} Secure Encryption Schemes},
howpublished = {Cryptology {ePrint} Archive, Paper 2025/077},
year = {2025},
doi = {10.1109/VCRIS63677.2024.10813389},
url = {https://eprint.iacr.org/2025/077}
}
