All, great thread and discussion. We ran into the same problems and invented a patent-pending algorithm to solve it. Please visit us
http://lottoken.org to learn more. Our white paper is at
http://bit.ly/lottoken_wp. We have even live contracts deployed for our platform. We believe we are the first ones to solve this problem. We would love to hear your feedback. We would greatly appreciate it.
PS: Only issue with provably fair scheme is that it requires multiple phases of operation. It may work for games like blackjack which are in real time but it will not work for lotteries or raffles where people just buy a ticket and just wait for the draw. Requiring them to take part in something like a two phase commit may give you provable random but it just would turn off people.
At
Lottoken.org that is why we purposely avoided this scheme. See our
white paper. We believe we are the first ones to solve this problem. We would love to hear your feedback. We would greatly appreciate it.
Lotteries in my option, especially bitcoin type of lotteries should just be based on the block hash when the lottery expires.
Lets say there is a lottery that expires in 24 hours, they should just use the block hash of the block that is solved after 24 hours and use it to determine the winning number.
With lotteries there isn't much interest because most people just play dice which has a lower edge in the gamblers favour.