ONE-TIME AUTHENTICATION SYSTEM, ONE-TIME AUTHENTICATION METHOD, AUTHENTICATION SERVER, PORTABLE TERMINAL AND ONE-TIME AUTHENTICATION PROGRAM

摘要

PROBLEM TO BE SOLVED: To establish authentication processing even under a condition that a user terminal and an authentication server cannot directly communicate with each other.;SOLUTION: First and second one-time codes are generated from a next-generation random number and a previous-generation random number at a user terminal 1 side. In an authentication server 2, first and second one-time codes for authentication are generated and stored by performing calculation using a hash function Hs on the first and second one-time codes. In the user terminal 1, according to the communication state, the calculation based on the hash function Hc is repeated at a frequency which is smaller than a predetermined frequency for selected random numbers by only a reduced frequency with respect to the next-generation random number and the previous-generation random number used for previously generated one-time codes, thereby generating a present second one-time code. In the authentication server 2, the calculation based on the hash function Hc is executed on the second one-time code by the reduced frequency, and a first or second one-time code for authentication is selected according to the communication state to perform authentication processing.;SELECTED DRAWING: Figure 1;COPYRIGHT: (C)2016,JPO&INPIT