Paper 2023/1295
Towards Minimizing Non-linearity in Type-II Generalized Feistel Networks
Abstract
Recent works have revisited blockcipher structures to achieve MPC- and ZKP-friendly designs. In particular, Albrecht et al. (EUROCRYPT 2015) first pioneered using a novel structure SP networks with partial non-linear layers (P-SPNs) and then (ESORICS 2019) repopularized using multi-line generalized Feistel networks (GFNs). In this paper, we persist in exploring symmetric cryptographic constructions that are conducive to the applications such as MPC. In order to study the minimization of non-linearity in Type-II Generalized Feistel Networks, we generalize the (extended) GFN by replacing the bit-wise shuffle in a GFN with the stronger linear layer in P-SPN and introducing the key in each round. We call this scheme Generalized Extended Generalized Feistel Network (GEGFN). When the block-functions (or S-boxes) are public random permutations or (domain-preserving) functions, we prove CCA security for the 5-round GEGFN. Our results also hold when the block-functions are over the prime fields F_p, yielding blockcipher constructions over (F_p)^*.
Metadata
- Available format(s)
-
PDF
- Category
- Secret-key cryptography
- Publication info
- Published elsewhere. Minor revision. CANS 2023
- Keywords
- blockciphersGeneralized Feistel networkssubstitution-permutation networksprovable securityprime fields
- Contact author(s)
-
yqzhao @ mail sdu edu cn
chun guo @ sdu edu cn
wjwang @ sdu edu cn - History
- 2023-09-02: approved
- 2023-08-31: received
- See all versions
- Short URL
- https://ia.cr/2023/1295
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2023/1295,
author = {Yuqing Zhao and Chun Guo and Weijia Wang},
title = {Towards Minimizing Non-linearity in Type-{II} Generalized Feistel Networks},
howpublished = {Cryptology {ePrint} Archive, Paper 2023/1295},
year = {2023},
url = {https://eprint.iacr.org/2023/1295}
}
