Method for authenticating an OTP and an instrument therefor

An instrument of authenticating an OTP, characterized in that, said instrument comprises:

• an obtaining module configured to obtain a token ID of an OTP token and the OTP generated by the OTP token;
• a first determining module configured to determine whether the OTP token has been authenticated successfully;
• a second determining module configured to determine whether an interval between authentication success time corresponding to the token ID in the database and the current system time is longer than a second predetermined time in case that the first determining module determines that the OTP token has been authenticated successfully;
• a setting module configured to set size of an authentication window to be a first predetermined time length in case that the first determining module determines that the OTP token has not been authenticated successfully;
• to set size of the authentication window to be a third predetermined time length in case that the second determining module determines that interval between the authentication success time and the current system time is longer than a second predetermined time length;
• to set size of the authentication window to be a fourth predetermined time length in case that the second determining module determines that interval between the authentication success time and the current system time is not longer than the second predetermined time length, in which the fourth predetermined time length is shorter than the third predetermined time length;
• a first authenticating module configured to compute an OTP by a time value selected from the authentication window and compare the OTP computed with the OTP obtained to authenticate the obtained OTP in case that the first determining module determines that the OTP has not been authenticated successfully;
• and
• a second authenticating module configured to authenticate the OTP obtained according to the authentication window and the authentication success time in which an OTP is computed by a time value selected from the authentication window and compared with the OTP obtained in case that the first determining module determines that the OTP token has been authenticated successfully wherein the said obtaining module, first determining module, second determining module, setting module, first authenticating module, and second authenticating module are installed on storage media and can be executed directly by hardware.