DPA resilience of rotation-symmetric S-boxes

Abstract

We regenerate the S-boxes that achieve the best possible trade-off between nonlinearity and differential uniformity in the class of 6×6 rotation-symmetric S-boxes (RSSBs) that are bijective, and then classify them in terms of transparency order. We find that although the transparency order ? 5.638 for the inverse function over double-struck F<inf>26</inf>, which can also be considered as rotation-symmetric, there exist RSSBs with the same nonlinearity and differential uniformity as those of the inverse function, having transparency order as low as 5.238. Motivated by this, we perform a steepest-descent-like iterative search algorithm in the class of 8×8 RSSBs and attain S-boxes with nonlinearity 104, differential uniformity 6, and transparency orders noticeably better than that of the AES S-box. Finally, replacing the AES S-box with those found by the search algorithm, we implement differential power analysis (DPA) attacks on SASEBO-GII and give a comparison of the results. © 2014 Springer International Publishing. © 2014 Elsevier B.V., All rights reserved.