video. They are PRNG with an additional property: the numbers unpredictable (what does that mean?: given n bits, it is computationally unfasable to construct the next bit!)

https://m.phys.org/news/2017-12-proof-randomness-future-digital.html

https://m.phys.org/news/2017-12-lensless-camera-d-images-scanning.html