Paper 2002/152
A note on Weak Keys of PES, IDEA and some Extended Variants
Jorge Nakahara Jr, Bart Preneel, and Joos Vandewalle
Abstract
This paper presents an analysis of the PES cipher in a similar setting as done by Daemen et al. at Crypto'93 for IDEA. The following results were obtained for 8.5 round PES: a linear weak-key class of size $2^{48}$; two distinct differential weak-key classes of size $2^{41}$; two differential-linear weak-key classes of size $2^{62}$. For 17-round PES (double-PES): a linear weak-key class of size $2^7$, and a differential weak-key class of size $2^7$ were found. Daemen suggested a modified key schedule for IDEA in order to avoid weak keys. We found a differential weak-key class of size $2^{83}$ for 2.5-round IDEA under his redesigned key schedule, and differential-linear relations for 3.5-round IDEA.
Note: comments are welcome !
Metadata
- Available format(s)
-
PDF PS
- Category
- Secret-key cryptography
- Publication info
- Published elsewhere. Unknown where it was published
- Keywords
- cryptanalysisblock ciphers
- Contact author(s)
- jorge nakahara @ esat kuleuven ac be
- History
- 2002-10-15: received
- Short URL
- https://ia.cr/2002/152
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2002/152,
author = {Jorge Nakahara Jr and Bart Preneel and Joos Vandewalle},
title = {A note on Weak Keys of {PES}, {IDEA} and some Extended Variants},
howpublished = {Cryptology {ePrint} Archive, Paper 2002/152},
year = {2002},
url = {https://eprint.iacr.org/2002/152}
}