Experiment content: in understanding the various authentication mechanism, on the basis of programming to realize one-time password mechanism, and discusses the dynamic password and one-time password mechanism of various implementation techniques, design key points: (1) write a one-time password program (2) run the password, a copy of Windows popup Windows on the screen, prompt the user to enter the password, and give prompt mode, (3) the user to enter the password, according to the one-time algorithm calculation, meet, given legitimate user tips; Otherwise illegal user tips, (4) run the password again. If the input with the same password for the first time, the system should be rejected, prompt illegal user, every tip and the input password is not the same, (5) write the design specification (contain formula, algorithms, the random number producing method, function calls and