Terms & Definitions
cryptographically sound random number generator
A cryptographically sound random number generator
is a very high quality random number generator that is almost certainly a
random number generator.
While the generator lacks a formal proof, there should exist a solid
and well reasoned argument for its cryptographic strength.
A cryptographically sound random number generator will pass
statistical tests with a very high level of confidence.
In fact, sound generators will pass tests at the same confidence level
as strong generators.
In particular, any standard battery of statistical tests for randomness,
when given a statistically significant amount of data, will not be able
to distinguish the random number generator from a
true random source.