| Céline Blondeau |  |
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Date of the talk: 10 February 2012
Cryptanalysis of Armadillo2
ARMADILLO2 is the recommended variant of a multi-purpose cryptographic primitive dedicated to hardware which has been proposed by Badel et al. in CHES 2010. This primitive based on data-dependant bit transpostion is very innovative. Using a generalisation of the parallel matching technique presented by Marìa Naya-Plasencia at CRYPTO 2011 we propose a meet-in-the-middle attack on the Armadillo function.The parallel matching method is a new technique to speed up complexities of the problem consisting in merging lists of big size. This method allow us to propose a key recovery attack of the FILMAC and the stream cipher application. Finally we propose a (second) preimage attack on its hashing application mode.
Our attacks have been validated experimentally by implementing cryptanalysis on scaled variants that match the theoretical predicted complexities.
This is a joint work with Mohamed Ahmed Abdelraheem, Marìa Naya-Plasencia, Marion Videau, and Erik Zenner.
