| 摘要 |
PROBLEM TO BE SOLVED: To reduce a redundant section in encryption processing, and to reduce a storage area of a mask value.SOLUTION: A first exclusive OR operation section takes exclusive OR between a plaintext and a mask value. A nonlinear conversion section masks input to a plurality of tables for nonlinear conversion, performs the nonlinear conversion according to the tables, outputs a value obtained by masking on an output side to values obtained by performing the nonlinear conversion. A linear conversion section performs linear conversion to a plurality of values output from the nonlinear conversion section. A first permutation section rearranges output of the linear conversion section. A second exclusive OR operation section takes exclusive OR between output of the first permutation section and an unmask value after completion of round processing. A second permutation section outputs a result obtained by rearranging output of the second exclusive OR operation section as a ciphertext. |
