| 摘要 |
It is aimed, for example, to reduce an amount of power consumption of an operation concerning data encryption or decryption and to make it difficult to perform a power analysis. In the case an exclusive OR operation between 32-bit input data and a 32-bit key is performed to obtain output data of 32 bits, the input data is kept in an input shift register 105 of 32 bits and the key is kept in a key shift register 106 of 32 bits. Then, 1 bit of the input data and 1 bit of the key are input into a serial operator 107, and an exclusive OR of 1 bit is obtained and shifted to the left end of the input shift register 105. The key shift register 106 performs a cyclic right shift. By performing the above thirty-two times, the operation of 32 bits is completed and the last result is kept in the input shift register 105. |
