See: https://en.wikipedia.org/wiki/Nothing_up_my_sleeve_number
(Or, of course, you could just not publish RNG standards based on public-key crypto ;-)
It seems there's enough evidence that NSA inserted the secret values in one standard already:
http://en.wikipedia.org/wiki/Dual_EC_DRBG
See: https://en.wikipedia.org/wiki/Nothing_up_my_sleeve_number
(Or, of course, you could just not publish RNG standards based on public-key crypto ;-)