[Resource Topic] 2016/831: Reducing the Number of Non-linear Multiplications in Masking Schemes

Welcome to the resource topic for 2016/831

Title:
Reducing the Number of Non-linear Multiplications in Masking Schemes

Authors: Jürgen Pulkus, Srinivas Vivek

Abstract:

In recent years, methods to securely mask S-boxes against side-channel attacks by representing them as polynomials over finite binary fields have become quite efficient. A good cost model for this is to count how many non-linear multiplications are needed. In this work we improve on the current state-of-the-art generic method published by Coron-Roy-Vivek at CHES 2014 by working over slightly larger fields than strictly needed. This leads us, for example, to evaluate DES S-boxes with only 3 non-linear multiplications and, as a result, obtain (25%) improvement in the running time for secure software implementations of DES when using three or more shares. On the theoretical side, we prove a logarithmic upper bound on the number of non-linear multiplications required to evaluate any (d)-bit S-box, when ignoring the cost of working in unreasonably large fields. This upper bound is lower than the previous lower bounds proved under the assumption of working over the field (\mathbb{F}{2^d}), and we show this bound to be sharp. We also achieve a way to evaluate the AES S-box using only 3 non-linear multiplications over (\mathbb{F}{2^{16}}).

ePrint: https://eprint.iacr.org/2016/831

Talk: https://www.youtube.com/watch?v=FqIVEdofXWs

See all topics related to this paper.

Feel free to post resources that are related to this paper below.

Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.

For more information, see the rules for Resource Topics .