Paper 2002/152
A note on Weak Keys of PES, IDEA and some Extended Variants
Jorge Nakahara Jr and 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