Patent ID: 8132010

Claim:
An authentication system, comprising: a host authenticating device; a portable authenticated unit connectable to the host authenticating device; the host authenticating device having: a random number generation device configured to generate a random number; a function determination signal generation device configured to generate a function determination signal for determining a function form, the authenticating device being configured to store the random number and the function determination signal; and a signal combining device configured to combine the function determination signal and the random number into a combined signal and transmit the combined signal to the authenticated unit; the portable authenticated unit having: a signal separation device configured to receive the combined signal and to separate the received combined signal into the function determination signal and the random number; a second function calculation device configured to calculate a function of the random number as a second calculation result using a determined function form determined by the function determination signal and configured to transmit the second calculation result back to the authenticating device; and a battery pack which provides power to the signal separation device and second function calculation device; the host authenticating device having: an inverse-function calculation device configured receive the second calculation result and to calculate an inverse function of the received second calculation result using a function form determined by the stored function determination signal; a comparison device configured to compare the stored random number with the inverse function calculation result; and a connecting device configured to effect a function connection of the authenticated unit to the authenticating device if it is detected that the stored random number equals the inverse function calculation result, and to reject the function connection of the authenticated unit to the authenticating device if it is detected that the stored random number does not equal the inverse function calculation result.