Alt Text: Avi Wigderson, an Israeli-born mathematician, won what's known as "the Nobel Prize of computing" for his work on randomness.
It's a fascinating field! Simplified: Make a machine that it is impossible to guess the likely outcome of with odds larger than 50/50.
We are talking any tiny advantageous guess here. If I predict 50/50 that a coin will go heads up, slight imbalances will cause it to go heads on average 51 times out of 100 tosses. Play for a dollar a million times, and I'm rich.
And if I know roughly how you will toss the coin, I can improve my prediction another tiny amount by knowing which side was up when you lift it up to toss it.
The field is about making a process that successfuly hides information so I can't know what state the internal workings of the coin tosser is at any time. It has huge overlap with cryptography.