Since a truly random number generator seems to be at the bottom of the problem, why has someone not used the most widespread random event of radioactivity to provide the input. You do not even need a radioactive source. natural radioactivity is enough. A narrow angle detector detects events, a timer ascertains the interval between events and creates a number determined by the interval. You can go on for as long as you like to creates a multi digit number which is truly random.