APPARATUS FOR ENCODING BLOCK DATA

摘要

PURPOSE: An apparatus for encoding block data is provided to encode block data by forming digital data as blocks and performing a functional operation for the blocked data and key data. CONSTITUTION: The first data division portion(310) divides input data into a multitude of data block. A key addition portion(320) performs a functional operation for the block data of the data division portion(310) and the sub key data. The second data division portion(325) divides the block data of the key addition portion into a couple of key addition sub block data. The first and the second data/key dependence operation portion(330,340) generates data/key depended data by performing an operation for key-added sub block data and the sub key data. The first function calculation portion(350) performs the functional operation for the key addition sub block data of the selected data couple. A substitution box(360) performs an inversion mapping operation for output data of the first function operation portion and generates corresponding converted block data. A constant addition portion(370) performs the functional operation for block data of the data conversion portion and generates calculated block data. A linear conversion portion(380) performs a linear conversion operation for the block data of the second function operation portion. A data combination portion(390) generates encoded data by adding output data of the linear conversion portion.