Paper 2020/1032 Original: eprint.iacr.org/2020/1032 ↗

Cryptanalysis of the MALICIOUS Framework

Tim Beyne
Chaoyun Li
Abstract

This note describes several attacks on the MALICIOUS framework for creating backdoored tweakable block ciphers. It is shown that, although the embedded malicious tweak pair itself is hard to recover, it is feasible to find additional weak tweak pairs that can be used to mount key-recovery attacks. Full-round attacks on most instances of LowMC-M are given. Our attacks are far from optimized and significant future improvements are to be expected. We focus on low-data attacks, since these are the most relevant for typical use-cases of LowMC. In addition, this implies that our attacks can not be prevented by limiting the amount of data that can be encrypted using the weak tweak pair. Despite our findings, we believe that the MALICIOUS framework can be used to create backdoored variants of LowMC provided that the parameters are modified.

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
Preprint.
History
2020-08-30: last updated
2020-08-27: published
Short URL
https://ia.cr/2020/1032
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2020/1032,
      author = {Tim Beyne and Chaoyun Li},
      title = {Cryptanalysis of the MALICIOUS Framework},
      howpublished = {Cryptology {ePrint} Archive, Paper 2020/1032},
      year = {2020},
      url = {https://eprint.iacr.org/2020/1032}
}
Note: In order to protect the privacy of readers, this archive does not use cookies or embedded third party content.