ENCODING DEVICE, ENCODING METHOD AND DECODING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an encoding device of simple configuration, by which high encoding efficiency and secrecy can be provided. SOLUTION: This device is composed of a code generating part 100 capable of generating a plurality of kinds of codes having mutually different code spaces to the event of encoding target data and an adaptive code type control part 200 for finding information for selecting a code type from the encoding target data in the past proximate to a present encoding time point, selecting and instructing a code type to be used at present or proximate encoding time point in future on the basis of this information and prepared key information. The code generating part 100 outputs the code of the instructed code type.