CRYPTOGRAPHIC METHOD FOR A WHITE-BOX IMPLEMENTATION

摘要

A cryptographic method is implemented in a white -box implementation thereof. The method comprises applying a plurality of transformations (802) each replacing an input word by an output word, and applying a diffusion operator (804) to a concatenation of a plurality of the output words for diffusing information represented by the output words among the output words. A key (806) to the cryptographic method comprises information representing the diffusion operator. The diffusion operator satisfies a property that a change of one bit in an input to the diffusion operator corresponds to a change of more than one bit in an output of the diffusion operator.