DATA CONVERTER, DATA CONVERTER METHOD AND PROGRAM FOR DATA CONVERTER AND COMPUTER-READABLE RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To make the configuration of an S-box converter simple, while ensuring security.SOLUTION: An S-box converter 21 of a non-linear data converter for performing non-linear conversion of data includes: a subfield converter 18 for inputting data to be converted, assuming the input data as an element of a field, converting the data by using an inverse element circuit using the subfield of the field and outputting converted data; and linear converters (affine converters) 85, 87 connected to the subfield converter 18. The linear converters (affine converters) 85, 87 for vector space GF(2)on GF(2) assumes data on GF(2) to be converted as an element of GF(2)and converts the data on GF(2) into data on GF(2).