Forgery Attacks on FlexAE and FlexAEAD

Maria Eichlseder; Daniel Kales; Markus Schofnegger

Paper 2019/679

Forgery Attacks on FlexAE and FlexAEAD

Maria Eichlseder, Daniel Kales, and Markus Schofnegger

Abstract

FlexAEAD is one of the round-1 candidates in the ongoing NIST Lightweight Cryptography standardization project. In this note, we show several forgery attacks on FlexAEAD with complexity less than the security bound given by the designers, such as a block reordering attack on full FlexAEAD-128 with estimated success probability about $2^{-54}$. Additionally, we show some trivial forgeries and point out domain separation issues.

Metadata

Available format(s): PDF
Publication info: Preprint. MINOR revision.
Keywords: authenticated encryption forgery attack NIST LWC
Contact author(s): daniel kales @ tugraz at
History: 2019-06-11: received
Short URL: https://ia.cr/2019/679
License: CC BY

BibTeX

@misc{cryptoeprint:2019/679,
      author = {Maria Eichlseder and Daniel Kales and Markus Schofnegger},
      title = {Forgery Attacks on FlexAE and FlexAEAD},
      howpublished = {Cryptology ePrint Archive, Paper 2019/679},
      year = {2019},
      note = {\url{https://eprint.iacr.org/2019/679}},
      url = {https://eprint.iacr.org/2019/679}
}