Symmetric Design

Keyed and unkeyed cryptographic permutations often iterate simple round functions. Substitution-permutation networks (SPNs) are an approach that is popular since the mid 1990s. One of the new directions in the design of these round functions is to …

We study approaches to generalized Feistel constructions with low-degree round functions with a focus on x - x^3 . Besides known constructions, we also provide a new balanced Feistel construction with improved diffusion properties. This then allows …