Random Number Generator is a computer program that generates previously unknown combinations of numbers. For the first time, Planet Poker offered to play poker for real money on the Internet. It happened at the beginning of 1998. The security issues of playing in this format have seriously interested representatives of many high-tech companies, in particular, Cigital. The employees wanted to make sure the algorithms of the program were reliable, and Planet Poker, in response to requests and as a demonstration of their confidence in the RNG, published its source code. It didn't take long for the errors to be discovered.The first leak that security experts found was that if the deck was randomly shuffled, the first card could not change from the 52nd. Because of such a trifle, a significant deviation from absolute randomness was already observed.The duty of any poker room is to guarantee the security of generating random sequences of cards and the reliability of information transfer between the server and the game client. In this regard, the use of pseudo-random software generators is unacceptable, since there is a risk of hacking them and getting sequences of numbers by attackers. In other words, crackers will know what cards their opponents have dealt.Also on PokerStars there is a concept of "sufficient degree of randomness". Until the program realizes that the value is high, the cards are not dealt. For example, if there is not enough user data to form a combination of numbers, the distribution will start later. The delay will be only a few tenths of a second, so the player will not notice it, but the number generator will have enough time to convert the stream of random bits into numbers.