ENCRYPTION PROCESSING DEVICE, ENCRYPTION PROCESSING METHOD, AND COMPUTER PROGRAM

摘要

PROBLEM TO BE SOLVED: To achieve miniaturization and cost reduction of a device by simplifying an encryption processing circuit that executes a round function repeatedly. SOLUTION: A round function is executed by inputting only a round key KAigenerated based on a first intermediate key KA in a round function execution part in a common key block encryption processing configuration for executing data conversion processing of the input data by repeatedly executing a plurality of round functions, applying the first intermediate key KA and a second intermediate key KB having a plurality of different data configurations generated based on a secret key K. An exclusive OR operation is executed with the input data for encryption processing, or the output data from the round function without inputting a key KBigenerated based on the second intermediate key KB in an F function in the round function part. This configuration allows the encryption processing circuit to be simplified, achieving miniaturization and cost reduction of the device. COPYRIGHT: (C)2009,JPO&INPIT