ENCIPHERING / DECIPHERING DEVICE, ENCIPHERING / DECIPHERING METHOD, DATA ENCIPHERING METHOD, AND IC CARD

摘要

A positive scramble signal processing in which either non-inverted data corresponding to processing unit data on plain or cipher text or the inverted data on all the bits are captured at random and is subjected to transposition/substitution corresponding to the non-inverted data and a negative scramble signal processing in witch the transposition/substitution corresponding to the inverted data is carried out are parallel conducted. The capturing either of the output signals corresponding to the respective processings in response to the data selection in the first signal processing is repeated a plurality of times, and the results of the final transposition/substitution are used as ciphered or deciphered data.