You would need to see the proof that BPP = P to see it.
It is not coming out yet, I'm planning to make money from it.
Even with such a random number generator, you would need a good seed--an "unguessable password" that someone could think of--to prevent others from predicting the outputted random numbers. If the "password" is secure, the numbers are random up to a point, in a certain sense. Without giving too much detail, there are "degrees of randomness."