Christoph Dobraunig
Maria Eichlseder
Florian Mendel
2017-03-07
<p>Simpira v1 is a recently proposed family of permutations, based on the AES round function. The design includes recommendations for using the Simpira permutations in block ciphers, hash functions, or authenticated ciphers. The designers' security analysis is based on computer-aided bounds for the minimum number of active S-boxes. We<br>
show that the underlying assumptions of independence, and thus the derived bounds, are incorrect. For family member Simpira-4, we provide di erential trails with only 40 (instead of 75) active S-boxes for the recommended 15 rounds. Based on these trails, we propose full-round collision attacks on the proposed Simpira-4 Davies-Meyer hash construction, with<br>
complexity 2<sup>82.62</sup> for the recommended full 15 rounds and a truncated 256-bit hash value, and complexity 2<sup>110.16</sup> for 16 rounds and the full 512-bit hash value. These attacks violate the designers' security claims that there are no structural distinguishers with complexity below 2<sup>128</sup>.</p>
https://doi.org/10.5281/zenodo.375528
oai:zenodo.org:375528
Zenodo
https://zenodo.org/communities/hector
https://zenodo.org/communities/eu
https://doi.org/
info:eu-repo/semantics/openAccess
Creative Commons Attribution 4.0 International
https://creativecommons.org/licenses/by/4.0/legalcode
SAC 2016, 31st ACM Symposium on Applied Computing, Pisa, Italy, 4-8 April 2016
Simpira, permutation-based cryptography, cryptanalysis, hash functions, collisions
Cryptanalysis of Simpira v1
info:eu-repo/semantics/conferencePaper