MESSAGE AUTHENTICATION CODE GENERATION DEVICE, MESSAGE AUTHENTICATION CODE VERIFICATION DEVICE, MESSAGE AUTHENTICATION CODE GENERATION METHOD, MESSAGE AUTHENTICATION CODE VERIFICATION METHOD, PROGRAM, AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a message authentication code in which call frequencies (frequencies of repeated processing) of a function are reduced while maintaining safety.;SOLUTION: A message authentication code generation device is disclosed which is provided with: a padding part; a message block generation part; an initial value setting part; and an intermediate variable calculation part. The message block generation part divides data M* into N pieces of c bit message blocks m_2n-1 and N pieces of b bit message blocks m_2n. The initial value setting part calculates the first intermediate variable v₀. The intermediate variable calculation part calculates an intermediate variable v_n by compressing a bit string obtained by coupling the message block m_2n to exclusive OR between the intermediate variable v_n-1 and the message block m_2n-1 by a compression function h for compressing a bit string of (c+b) bit into a bit string of c bit, repeats calculation of the intermediate variable v_n from n=1 to n=N to calculate an intermediate variable v_N.;COPYRIGHT: (C)2009,JPO&INPIT