International Association for Cryptologic Research

International Association
for Cryptologic Research

IACR News item: 18 July 2015

Anne Canteaut, Sébastien Duval, Gaëtan Leurent
ePrint Report ePrint Report
The aim of this work is to find large S-Boxes, typically operating on 8

bits, having both good cryptographic properties and a low implementation

cost. Such S-Boxes are suitable building-blocks in many lightweight

block ciphers since they may achieve a better security level than

designs based directly on smaller S-Boxes. We focus on S-Boxes

corresponding to three rounds of a balanced Feistel and of a balanced

MISTY structure, and generalize the recent results by Li and Wang on the

best differential uniformity and linearity offered by such a

construction. Most notably, we prove that Feistel networks supersede

MISTY networks for the construction of 8-bit permutations. Based on

these results, we also provide a particular instantiation of an 8-bit

permutation with better properties than the S-Boxes used in several

ciphers, including Robin, Fantomas or CRYPTON.

Expand

Additional news items may be found on the IACR news page.