Testing hardware random number generators?

Question

1. I would like to know how to test hardware random number generators.
2. What techniques, tools or tricks to solve the problem ?
3. Any practical difficulties, implementation complexities etc.

Answer 1

NIST has a lot of information on testing random number generators at http://csrc.nist.gov/groups/ST/toolkit/rng/index.html that might be of value to you.