Paper 2021/238
Two Sides of The Same Coin: Weak-Keys and More Efficient Variants of CRAFT
Gregor Leander and Shahram Rasoolzadeh
Abstract
CRAFT is a lightweight tweakable Substitution-Permutation-Network (SPN) block cipher optimized for efficient protection of its implementations against Differential Fault Analysis (DFA) attacks. In this paper, we present an equivalent description of CRAFT up to a simple mapping on the plaintext, ciphertext and round tweakeys. We show that the new representation, for a sub-class of keys, leads to a new structure which is a Feistel network, i.e., with half state non-linear operation and half state key addition. This has two interesting consequences: First, the new structure of the cipher is less resistant against differential and linear cryptanalyses. Second, it allows a more efficient implementation of the cipher.
Metadata
- Available format(s)
- Category
- Secret-key cryptography
- Publication info
- Preprint. MINOR revision.
- Keywords
- CRAFTpartial key additionpartial non-linear layer
- Contact author(s)
- shahram rasoolzadeh @ ru nl
- History
- 2022-01-29: last of 3 revisions
- 2021-03-02: received
- See all versions
- Short URL
- https://ia.cr/2021/238
- License
-
CC BY