Quantum Attacks on Type-1 Generalized Feistel Schemes

Hong-Wei Sun; Bin-Bin Cai; Su-Juan Qin; Qiao-Yan Wen; Fei Gao

Paper 2023/776

Quantum Attacks on Type-1 Generalized Feistel Schemes

Hong-Wei Sun, Beijing University of Posts and Telecommunications

Bin-Bin Cai

Su-Juan Qin

Qiao-Yan Wen

Fei Gao

Abstract

Generalized Feistel schemes (GFSs) are extremely important and extensively researched cryptographic schemes. In this paper, we investigate the security of Type-1 GFS in quantum circumstances. On the one hand, in the qCCA setting, we give a new quantum polynomial-time distinguisher on -round Type-1 GFS with branches , which extends the previous results by rounds. This leads to a more efficient analysis of type-1 GFS, that is, the complexity of some previous key-recovery attacks is reduced by a factor of , where is the key length of the internal round function. On the other hand, for CAST-256, which is a certain block cipher based on Type-1 GFS, we give a 17-round quantum distinguisher in the qCPA setting. Based on this, we construct an -round quantum key-recovery attack with complexity .

Metadata

Available format(s): PDF
Category: Attacks and cryptanalysis
Publication info: Preprint.
Keywords: Generalized Feistel scheme CAST-256 Simon algorithm Quantum cryptanalysis Quantum algorithm
Contact author(s): Sunhw @ bupt edu cn
History: 2023-08-17: revised; 2023-05-27: received; See all versions
Short URL: https://ia.cr/2023/776
License: CC BY

BibTeX

@misc{cryptoeprint:2023/776,
      author = {Hong-Wei Sun and Bin-Bin Cai and Su-Juan Qin and Qiao-Yan Wen and Fei Gao},
      title = {Quantum Attacks on Type-1 Generalized Feistel Schemes},
      howpublished = {Cryptology {ePrint} Archive, Paper 2023/776},
      year = {2023},
      url = {https://eprint.iacr.org/2023/776}
}