Social Security number code "cracked" For people born after 1988 — when the government began issuing numbers at birth — the researchers were able to identify, in a single attempt, the first five Social Security digits for 44 percent of individuals. And they got all nine digits for 8.5 percent of those people in fewer than 1,000 attempts.
It actually is difficult to generate a random number. Introduction to Randomness and Random Numbers. That site generates randomness via atmospheric noise.