Paper 2024/1634

On Constructing Pseudorandom Involutions: Feistel variants using a single round function

Chun Guo, Shandong University
Meiqin Wang, Shandong University
Weijia Wang, Shandong University
Abstract

An involution is a permutation that is the inverse of itself. Involutions have attracted plenty attentions in cryptographic community due to their advantage regarding hardware implementations. In this paper, we reconsider constructing {\it pseudorandom involutions}. We demonstrate two constructions. First, the 4-round Feistel network {\it using the same random function (Feistel-SF) in every round} is a pseudorandom involution. This shows the Feistel-SF construction still provides non-trivial cryptographic strength. To complement, we also show insecurity of 3-round Feistel-SF by exhibiting an attack. Second, a ``mirrored'' variant of the Naor-Reingold construction with component reusing yields a pseudorandom involution.

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
Preprint.
Keywords
involutionindistinguishabilityFeistelNaor-Reingold
Contact author(s)
chun guo @ sdu edu cn
mqwang @ sdu edu cn
wjwang @ sdu edu cn
History
2024-10-14: approved
2024-10-11: received
See all versions
Short URL
https://ia.cr/2024/1634
License
No rights reserved
CC0

BibTeX

@misc{cryptoeprint:2024/1634,
      author = {Chun Guo and Meiqin Wang and Weijia Wang},
      title = {On Constructing Pseudorandom Involutions: Feistel variants using a single round function},
      howpublished = {Cryptology {ePrint} Archive, Paper 2024/1634},
      year = {2024},
      url = {https://eprint.iacr.org/2024/1634}
}
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