In other words, why the AIS-31 compliant true random number generator (TRNG) generates a more random 256bit number rather than physical coin fliped 256 times?
I do not understand the limitations on AIS-31 compliant. Maybe someone who has more knowledge can help us better ( i would move this topic to technical discussion board for better inputs from community and less yobit spammers).
But there are limitations on randomness of flipping a coin over and over again.
1 - muscular memory - i don't know if that expression is correct, I am talking about you doing the exactly same movement 256 times is not totally random. Your movement may not be 50-50, but 30-70, as it is the same over and over again. Maybe if you asked to different 256 people flip the coin once, it would have a better randomness.
2 - coin may have not be completely balanced, which could also lead to biased results (not 50-50).
But anyway, as I said before, I think it is enough randomness for a priavate key generation. Don't know if it is better or not than AIS-31. But flipping a coin is not perfectly random imo.