ENCRYPTION DEVICE, ENCRYPTION METHOD, AND COMPUTER PROGRAM

摘要

It is possible to realize a common key block encryption configuration capable of increasing difficulty of the key analysis and increasing safety and mounting efficiency. A key schedule unit of an encryption device executing a common key block encryption process inputs a secret key in an encryption function containing a round function to be used in the encryption unit so as to generate an intermediate key and applies results of full bijective conversion based on the intermediate key and the secret key and results of exclusive OR operation of the full bijective conversion data to the round key. With this configuration, it is possible to generate a round key based on the intermediate key generated by using the encryption function having a guaranteed safety, increase the key analysis difficulty, simplify the configuration of the key schedule unit, and enhance the mounting efficiency.