Related-key Differential Cryptanalysis of Full Round CRAFT

Muhammad ElSheikh; Amr M.  Youssef

Paper 2019/932

Related-key Differential Cryptanalysis of Full Round CRAFT

Muhammad ElSheikh and Amr M. Youssef

Abstract

$CRAFT$ is a lightweight tweakable block cipher introduced in FSE 2019. One of the main design criteria of $CRAFT$ is the efficient protection of its implementations against differential fault analysis. While the authors of $CRAFT$ provide several cryptanalysis results in several attack models, they do not claim any security of $CRAFT$ against related-key differential attacks. In this paper, we utilize the simple key schedule of $CRAFT$ to propose a systematic method for constructing several repeatable 2-round related-key differential characteristics with probability $2^{- 2}$ . We then employ one of these characteristics to mount a key recovery attack on full-round $CRAFT$ using $2^{31}$ queries to the encryption oracle and encryptions, and 64-bit blocks of memory. Additionally, we manage to use 8 related-key differential distinguishers, with 8 related-key differences, in order to mount a key recovery attack on the full-round cipher with queries to the encryption oracle, encryptions and about 64-bit blocks of memory. Furthermore, we present another attack that recovers the whole master key with queries to the encryption oracle and only encryptions with blocks of memory using 16 related-key differential distinguishers.

Metadata

Available format(s): PDF
Category: Secret-key cryptography
Publication info: Published elsewhere. SPACE 2019
Keywords: CRAFT Related-Key Tweakable
Contact author(s): m_elshei @ encs concordia ca
History: 2019-11-04: revised; 2019-08-18: received; See all versions
Short URL: https://ia.cr/2019/932
License: CC BY

BibTeX

@misc{cryptoeprint:2019/932,
      author = {Muhammad ElSheikh and Amr M.  Youssef},
      title = {Related-key Differential Cryptanalysis of Full Round {CRAFT}},
      howpublished = {Cryptology {ePrint} Archive, Paper 2019/932},
      year = {2019},
      url = {https://eprint.iacr.org/2019/932}
}