To expand on that a little, the main property you're looking for is that if I give you the N random numbers that have already been generated you can't predict w

To expand on that a little, the main property you're looking for is that if I give you the N random numbers that have already been generated you can't predict what the next one will be with certainty beyond random chance. https://en.wikipedia.org/wiki/Cryptographically_secure_pseudorandom_number_generator#Requirements https://en.wikipedia.org/wiki/Cryptographically_secure_pseud... has more detail.