International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

Security Analysis of BLAKE2's Modes of Operation

Authors:
Atul Luykx , Dept. Electrical Engineering, ESAT/COSIC, KU Leuven, and iMinds
Bart Mennink , Dept. Electrical Engineering, ESAT/COSIC, KU Leuven, and iMinds
Samuel Neves , CISUC, Dept. of Informatics Engineering, University of Coimbra
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DOI: 10.13154/tosc.v2016.i1.158-176
URL: http://tosc.iacr.org/index.php/ToSC/article/view/540
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Abstract: BLAKE2 is a hash function introduced at ACNS 2013, which has been adopted in many constructions and applications. It is a successor to the SHA-3 finalist BLAKE, which received a significant amount of security analysis. Nevertheless, BLAKE2 introduces sufficient changes so that not all results from BLAKE carry over, meaning new analysis is necessary. To date, all known cryptanalysis done on BLAKE2 has focused on its underlying building blocks, with little focus placed on understanding BLAKE2’s generic security. We prove that BLAKE2’s compression function is indifferentiable from a random function in a weakly ideal cipher model, which was not the case for BLAKE. This implies that there are no generic attacks against any of the modes that BLAKE2 uses.
BibTeX
@article{tosc-2016-28136,
  title={Security Analysis of BLAKE2's Modes of Operation},
  journal={IACR Trans. Symmetric Cryptol.},
  publisher={Ruhr-Universität Bochum},
  volume={2016, Issue 1},
  pages={158-176},
  url={http://tosc.iacr.org/index.php/ToSC/article/view/540},
  doi={10.13154/tosc.v2016.i1.158-176},
  author={Atul Luykx and Bart Mennink and Samuel Neves},
  year=2016
}