APPARATUS AND METHOD FOR EVALUATING RANDOMNESS OF FUNCTIONS, RANDOM FUNCTION GENERATING APPARATUS AND METHOD, AND RECORDING MEDIUM HAVING RECORDED THEREON PROGRAMS FOR IMPLEMENTING THE METHODS.

摘要

In the evaluation of the randomness of an S-box, measures ofresistance to higher order cryptanalysis, interpolation cryptanalysis,partitioning cryptanalysis and differential-linear cryptanalysis and necessaryconditions for those measures to have resistance to each cryptanalysis areset,then for functions as candidates for the S-box, it is evaluated whether one orall of the conditions are satisfied, and those of the candidate functions forwhich one or all of the conditions are satisfied are selected as required. Itis also possible to further evaluate the resistance of such selected functionsto at least one of differential cryptanalysis and linear cryptanalysis andselect those of the candidate functions which are resistant to at least one ofthe cryptanalyses as required.