Authentication encryption apparatus, authentication encryption method, and authentication encryption program

摘要

An authentication cipher that is a one-pass and one-rate authentication cipher that can be processed in parallel and that can execute the entire encryption and decryption process with only one encryption function. The authentication encryption device applies a 2-round Feistel structure using an encryption function with an auxiliary variable as a round function to the input plaintext or ciphertext every two blocks. The authentication encryption means which produces | generates is provided. The authentication encryption means, for example, the ciphertext chunk CC [i] corresponding to the i-th plaintext chunk MC [i] = (M [i_1], M [i_2]) when the plaintext is divided into chunks every two blocks = (C [i_1], C [i_2]), C [i_1] = F_K ((N, Tw_i_1), M [i_1]) xor M [i_2], C [i_2] = F_K ((N, Tw_i_2) , C [i_1]) xor M [i_1].