another method of acquiring randomness

[ianG]

https://medium.com/the-physics-arxiv-blog/quantum-random-number-generator-created-using-a-smartphone-camera-602f88552b64

Bruno Sanguinetti and pals at the University of Geneva in Switzerland 
have worked out how to generate random numbers on an ordinary smartphone 
using genuine quantum processes. And they say their new technique can 
produce random numbers at the rate of 1 megabit per second, more than 
enough for most security applications.

The quantum process that these guys exploit is the way light sources 
emit photons. Because each emission is a quantum process, the instant of 
emission cannot be predicted. So the number of photons that a light 
source emits in a unit of time will always vary by an amount that is 
entirely random. ...