I've always wondered: why aren't ADCs (e.g. mic input) and temperature sensors considered a good source of entropy, particularly if the lower bits are taken?
If you just want any old entropy, and don't care about proving to someone else that your entropy is good, these are acceptable. But it's honestly really easy to get entropy on that grate, and thanks to modern cryptographically secure PRNG, you don't need a lot of 'real' entropy. You can stretch it out forever.
If you want/need to be able to argue to a third party that your entropy was good, you can spend a bit more.
How do you convince anyone that your mic input was actual real mic input, and not just a sequence of bits you made up to be convenient for you?
I've always wondered: why aren't ADCs (e.g. mic input) and temperature sensors considered a good source of entropy, particularly if the lower bits are taken?