Welcome to the resource topic for
**2022/1141**

**Title:**

An Optimal Universal Construction for the Threshold Implementation of Bijective S-boxes

**Authors:**
Enrico Piccione, Samuele Andreoli, Lilya Budaghyan, Claude Carlet, Siemen Dhooghe, Svetla Nikova, George Petrides, Vincent Rijmen

**Abstract:**

Threshold implementation is a method based on secret sharing to secure cryptographic ciphers (and in particular S-boxes) against differential power analysis. Until now, threshold implementations were only constructed for specific types of functions and some small S-boxes, but no general construction for all S-boxes was ever presented. The lower bound for the number of shares of threshold implementation is t+1, where t is the algebraic degree of the S-box. Since the smallest number of shares t+1 is not possible for all S-Boxes, as proven by Bilgin et al. in 2015, then there does not exist a universal construction with t+1 shares. Hence, if there is a universal construction working for all permutations then it should work with at least t+2 shares. In this paper, we present the first optimal universal construction with t+2 shares. This construction enables low latency hardware implementations without the need for randomness. In particular, we apply this result to find the first two uniform sharings of the AES S-box. Area and performance figures for hardware implementations are provided.

**ePrint:**
https://eprint.iacr.org/2022/1141

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 .