A disclosed data encoding apparatus includes: an arbitrary number of storage units; a data transfer control unit dividing input data into data blocks in accordance with the arbitrary number of storage units and transferring the data blocks to each storage unit; and encoding units having the same number as the storage units, the encoding units encoding the data blocks using a different cryptographic key for each storage unit while the data blocks are transferred by the data transfer control unit, wherein each storage unit stores the data blocks encoded by the encoding units.