S‐box on subgroup of Galois field based on linear fractional transformation

Abstract

The erection of a substitution box based on linear fractional transformation applied on the subgroup of multiplicative part of Galois field GF(28) is studied. The establishment of constrained linear fractional transformation on the elements of the subgroup is intricacy of the problem. The robustness of the proposed substitution box against renowned algebraic and statistical attacks is gauged to enumerate its confusion creating ability. The analysis is accomplished by finding non-linearity, approximation probabilities and strict avalanche criterion. The majority logic criterion is employed to guesstimate the efficacy of substitution box in image encryption applications.