http://cypherpunks.venona.com/date/1993/05/msg00213.html
Back in the old days, Tim May would occasionally talk about the Kolmogorov-Chaitin theories about randomness - Kolmogorov complexity gives you a lot of deep explanations about this sort of problem. Alas, I never actually *read* those papers, but there's been a lot of mathematical thought about what randomness means.
