Paper 2010/593 Original: eprint.iacr.org/2010/593 ↗
Differential Attack on Five Rounds of the SC2000 Block Cipher
Abstract
The SC2000 block cipher has a 128-bit block size and a user key of 128, 192 or 256 bits, which employs a total of 6.5 rounds if a 128-bit user key is used. It is a CRYPTREC recommended e-government cipher. In this paper we describe two 4.75-round differential characteristics with probability $2^{-126}$ of SC2000 and seventy-six 4.75-round differential characteristics with probability $2^{-127}$. Finally, we present a differential cryptanalysis attack on a 5-round reduced version of SC2000 when used with a 128-bit key; the attack requires $2^{125.68}$ chosen plaintexts and has a time complexity of $2^{125.75}$ 5-round SC2000 encryptions. It suggests for the first time that the safety margin of SC2000 with a 128-bit key decreases below one and a half rounds.
Metadata
- Available format(s)
PDF- Category
- Secret-key cryptography
- Publication info
- Preprint.
- History
- 2010-12-04: last updated
- 2010-11-23: published
- Short URL
- https://ia.cr/2010/593
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2010/593,
author = {Jiqiang Lu},
title = {Differential Attack on Five Rounds of the SC2000 Block Cipher},
howpublished = {Cryptology {ePrint} Archive, Paper 2010/593},
year = {2010},
url = {https://eprint.iacr.org/2010/593}
}