ENCRYPTION METHOD, DECRYPTION METHOD, DEVICE, AND PROGRAM

摘要

An encryption/decryption method comprises by using a generalized Feistel structure in which data is divided into n pieces and mixing processing with key data is performed, diffusion processing, in which data transformation via linear operation is executed, is performed at least once between rounds of the generalized Feistel structure, wherein. As the diffusion processing, linear transformation is performed in which each of n pieces of output data is operated on by two or more pieces of input data. The method is adapted for encryption or decryption.