I was wondering how to give a hint to someone to imagine the size of a 256 bits key speaking about Bitcoin (even if private key in Bitcoin are 160 bits if I remember) and not with the number of atoms in the universe or things like that. I wanted to compare to French lottery (https://fr.wikipedia.org/wiki/Loto#Depuis_2008_:_nouvelle_version) where you have 1 chance on 19 068 840 to win. I wanted something like "Finding a 256 bits key is like winning lottery n times in a row" but is the independency of results ("in a row") change the calculation ? Is the answer "simply" log_19068840(2^256) so about 11 (https://www.wolframalpha.com/input/?i=log%5B19068840%2C2%5E256%5D)?
Thank you very much.