Paper 2025/025
Chosen-Ciphertext Security for Inner Product FE: Mutli-Client and Multi-Input, Generically
, DIENS, École normale supérieure, CNRS, Inria, PSL University, Paris, FranceAbstract
Functional Encryption is a powerful cryptographic primitive that allows for fine-grained access control over encrypted data. In the multi-user setting, especially Multi-Client and Multi-Input, a plethora of works have been proposed to study on concrete function classes, improving security, and more. However, the CCA-security for such schemes is still an open problem, where the only known works are on Public-Key Single-Client FE (Benhamouda, Bourse, and Lipmaa, PKC'17). This work provides the first generic construction of CCA-secure Multi-Client FE for Inner Products, and Multi-Input FE for Inner Products, with instantiations from $\mathsf{SXDH}$ and $\mathsf{DLIN}$ for the former, and $\mathsf{DDH}$ or $\mathsf{DCR}$ for the latter. Surprisingly, in the case of secret key MIFE we attain the same efficiency as in the public key single-client setting. In the MCFE setting, a toolkit of CCA-bootstrapping techniques is developed to achieve CCA-security in its $\mathit{secret~key}$ setting.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Preprint.
- Keywords
- Functional EncryptionSecurity Notions
- Contact author(s)
- ky nguyen @ ens fr
- History
- 2025-01-08: approved
- 2025-01-07: received
- See all versions
- Short URL
- https://ia.cr/2025/025
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2025/025,
author = {Ky Nguyen},
title = {Chosen-Ciphertext Security for Inner Product {FE}: Mutli-Client and Multi-Input, Generically},
howpublished = {Cryptology {ePrint} Archive, Paper 2025/025},
year = {2025},
url = {https://eprint.iacr.org/2025/025}
}
