| 摘要 |
A device for generating a message authenticator generates a value E of a number of bits that is i times the number of e bits using a key K and a message M as inputs, divides the value E for each e bit, and generates values M[1], …, M[i]. In the process, the device for generating a message authenticator generates the value E such that at least some of the bits of the key K are included in the value M[1] and the value M[i] among the values M[1], …, M[i]. The device for generating a message authenticator: uses a value S[j-1] and a value M[j] as inputs in sequence for the integers j=1, …, i, where S[0] is a given value; calculates a value R[j] with the function g[j]; and substitutes the calculated value R[j] with a substitute function P[j] to calculate the value S[j]. The device for generating a message authenticator uses a value S[i] to generate an authenticator T for the message M. |
