Want a FIPS 140-2 RNG [wikipedia.org] ? Look at the universe. The cosmic background radiation bathes Earth in enough random numbers to encrypt everything forever. Using the cosmic background radiation – the “echo of the Big Bang” – as a random number generation isn't a new idea, but a couple of scientists have run the slide-rule over measurements of the CMB power spectrum and reckon it offers a random number space big enough to beat any current computer.
Not in terms of protecting messages against any current decryption possibility: the CMB's power spectrum offers a key space “too large for the encryption/decryption capacities of present computer systems”. A straightforward terrestrial radio telescope, this Arxiv paper states [arxiv.org], should be good enough to make “astrophysical entropy sources accessible on comparatively modest budgets”.
http://www.theregister.co.uk/2015/11/12/big_bang_left_us_with_a_perfect_random_number_generator/ [theregister.co.uk]