Differential analysis of the NBC algorithm based on mixed integer linear programming model

This paper mainly studies mixed integer linear programming (MILP)-based cryptanalysis on round-reduced NBC algorithm with generalized Feistel structure. First, each component of the is equivalently described by inequality equations, and propagation rules differential characteristics approximation are described, an automatic search model mode mask based MILP established, minimum number active S-boxes corresponding paths obtained. Second, according to algorithm's 16-bit block pull-wire position permutation characteristics, optimal full diffusion rounds NBC-128 NBC-256 obtained using approximate matrix multiplication theory be six eight respectively. Finally, algorithm, impossible set input patterns traversed obtain 11-round distinguishers 14-round