International Association for Cryptologic Research

International Association
for Cryptologic Research


Paper: Cryptanalysis of Reduced round SKINNY Block Cipher

Sadegh Sadeghi , Department of Mathematics, Faculty of Mathematical Sciences and Computer, Kharazmi University, Tehran
Tahereh Mohammadi , Electrical Engineering Department, Shahid Rajaee Teacher Training University, Tehran
Nasour Bagheri , Electrical Engineering Department, Shahid Rajaee Teacher Training University; School of Computer Science, Institute for Research in Fundamental Sciences (IPM), Tehran
DOI: 10.13154/tosc.v2018.i3.124-162
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Abstract: SKINNY is a family of lightweight tweakable block ciphers designed to have the smallest hardware footprint. In this paper, we present zero-correlation linear approximations and the related-tweakey impossible differential characteristics for different versions of SKINNY .We utilize Mixed Integer Linear Programming (MILP) to search all zero-correlation linear distinguishers for all variants of SKINNY, where the longest distinguisher found reaches 10 rounds. Using a 9-round characteristic, we present 14 and 18-round zero correlation attacks on SKINNY-64-64 and SKINNY- 64-128, respectively. Also, for SKINNY-n-n and SKINNY-n-2n, we construct 13 and 15-round related-tweakey impossible differential characteristics, respectively. Utilizing these characteristics, we propose 23-round related-tweakey impossible differential cryptanalysis by applying the key recovery attack for SKINNY-n-2n and 19-round attack for SKINNY-n-n. To the best of our knowledge, the presented zero-correlation characteristics in this paper are the first attempt to investigate the security of SKINNY against this attack and the results on the related-tweakey impossible differential attack are the best reported ones.
Video from TOSC 2018
  title={Cryptanalysis of Reduced round SKINNY Block Cipher},
  journal={IACR Transactions on Symmetric Cryptology},
  publisher={Ruhr-Universität Bochum},
  volume={2018, Issue 3},
  author={Sadegh Sadeghi and Tahereh Mohammadi and Nasour Bagheri},