th said first combined data, and causing said memory means to generate new output data; e. repeating steps (c) and (d) n times, n > 0; f. repeating steps (c), (d), and (e) for each remaining digit of said account number; g. repeating steps (c), (d) and (e) for one digit of said account number; h. storing output data from said memory means, said data including a first digit of generated secret numb