BLOCK ENCRYPTION DEVICE USING AUXILIARY CONVERSION

摘要

A data transformation apparatus having: a data processing unit for inputti ng key data and performing at least one of encryption of data and decryption of data; and, a key generating unit for generating key data to be used by the data processing unit and supplying the key data to the data processing unit, the data transformation apparatus comprising a non-linear function unit (F) including: a key functio n unit for performing a logical operation of data to be transformed and the key data; a n S function unit for converting data to be transformed into other data; and a P function unit for performing a logical operation among pieces of data to be transformed, and wherein the key function unit is placed between the S function unit and the P function unit in the non-linear function unit (F).