Show HN: My friends just built a Bitcoin casino (opens in new tab)

+1

True, although by the time you've signed up and proven ID, you've lost the 'spontaneous' appeal of the site (making it quick and easy to have a bet). I guess the site still has the advantage of low-cost money transfers and no risk of chargebacks, so bitcoins may have a use here.

I wonder if it is possible to use bitcoins and comply with the UK gambling restrictions against money laundering? At first glance, it looks impossible, bitcoins being (supposedly) untraceable. However, you might be able to comply if you insist that winnings are always paid back to the same bitcoin wallet that they came from. The justification here being that your website won't have 'washed' the money any further than it was already laundered.

Or the regular police would suffice, in this case.

My gut feeling is that since it's using a repeatable number-generator (without which it wouldn't be "provably fair" as you have described), it might be possible to game by client-side pre-evaluation of the sequence. Even if the whole sequence isn't finalized until the initial bitcoin transfer is made (I only have the information provided on the site to go on...), it might be possible (for example) to strategically transfer/commit, at a known/manageable cost, but simply not play the hand (abandon the transfer) unless the payout is greater than your expenses, circumventing the game's long-run behavior entirely. We don't have server code to look at (github?), but we all have access to python's libraries and can seed our own PRNG after the transfer in order to evaluate the hand/sequence.

Not exactly. It means, you can check two things after you have played:

1. The random number was generated before you even started. So the house could not change the number depending on the actual bets.

2. Distribution of random numbers over time. E.g. if the rule is "win when uniformly random number 0..1 is greater than 0.5", then you can check the history of all random numbers played (at least with your bets, if you don't trust the house to show real bets for other players) and calculate the properties of actual distribution. If it does not contain a significant offset, then it's fair. (Small deviations can be seen simply as part of the fee.)

I know what probably fair means, just that I don't understand why it would be so big deal. Why would the casinos cheat if the probabilities are on their side in every case?

it's all about reputation. all games are made public online. all payouts are displayed on the website. if things went array for any reason it would be public knowledge very quickly and thus the end of the site.

ah - got it.

Okay, I revoked the accusation. I'm afraid my instinct is to mistrust people by default. We'll soon see if my instincts are wrong.

Thanks for the reply!

There's actually a lot of them. Is there a way to just modify it so that I can withdraw using just the private URL? (Otherwise, I'll send another support email [from gummybean] with the addresses.)

we are not a casino. this is a tiny side product built by a couple of guys over a couple of days to explore bitcoin.

fixed. thanks

Because, if you lose once, you lose?