PhatHash is an online blackjack casino that demonstrates the honesty of its virtual decks by making their mathematical "hashes" available as they enter play. During and after play, the hashing algorithm can be applied to the visible portion of the deck to ensure that the house isn't changing the cards to improve their odds.
# The MD5 hash (a standard and well-known cryptographic function) of that deck is calculated.
# This MD5 hash is published openly and immediately on on the PhatHash Log Page, becoming completely transparent information that anyone can examine. Anyone, at any time, including our competitors!
# The croupier in the multiplayer BJ room tells everyone what the new hash is. Anyone playing or auditing the game can verify that it is the same data that appears on the PhatHash Log Page at that moment.
# Play then proceeds with the new shoe of 520 cards. Note that anyone can audit the cards as they are dealt to the player(s) over the course of the hands to follow. Eventually in the course of play that shoe will be complete and it will be time to shuffle a new shoe.
(via Oblomovka)
Update: A reader writes, "The integrity of the deck doesn't matter worth *anything*. The hash insures (or is supposed to) that they haven't changed the cards middeck. There is NO protection against stacking the deck."
