To provide an encryption processing device and an encryption processing method whose security level is high by enhancing the difficulty in cryptanalysis by means of measurement of electric power consumption.
The encryption processing device wherein common key encryption processing comprising a plurality of stages of round functions is so constituted that F function output of each stage, that is intermediate data output value outputted from an S box via a replacement section, is stored as it is in an R register and an L register of a first data storage section and the reverse data of the output value is stored in an R' register and an L' register of a second data storage section. Thus, the sum of Humming weight in register storing processing can be kept constant. As a result, the difficulty in acquiring Humming weight information concerning confidential information such as key information based on the observation of the change in device power consumption is enhanced, and the difficulty in cryptanalysis can be enhanced.
KANAMARU MASASHI
| JP2004038318A | 2004-02-05 | |||
| JPH10333569A | 1998-12-18 | |||
| JP2000066585A | 2000-03-03 | |||
| JP2002311826A | 2002-10-25 |
Eiji Yamada
Toshio Sawada