Page "Cryptographically secure pseudorandom number generator" Paragraph 11

* Every CSPRNG should satisfy the next-bit test.

That is, given the first < var > k </ var > bits of a random sequence, there is no polynomial-time algorithm that can predict the (< var > k </ var >+ 1 ) th bit with probability of success better than 50 %.

Andrew Yao proved in 1982 that a generator passing the next-bit test will pass all other polynomial-time statistical tests for randomness.