S-box, SET, Match: A Toolbox for S-box Analysis

Boolean functions and substitution boxes (S-boxes) represent the only nonlinear part in many algorithms and therefore play the crucial role in their security. Despite the fact that some algorithms today reuse theoretically secure and carefully constructed S-boxes, there is a clear need for a tool that can analyze security properties of S-boxes and hence the corresponding primitives. This need is especially evident in the scenarios where the goal is to create new S-boxes. Even in the cases when some common properties of S-boxes are known, we believe it is prudent to exhaustively investigate all possible sets of cryptographic properties. In this paper we present a tool for the evaluation of Boolean functions and S-boxes suitable for cryptography.