BitLotto was likely the first blockchain-based "provably fair". It uses the transaction ID as the "ticket", and the results of a large government-run lottery to determine the winning numbers.
SatoshiDICE became a blockbuster (pun intended) method for online gambling. It uses the transaction ID to determine the "lucky number" (...
[Going to answer this one myself.]
Unlike games of chance where you need to trust a machine or a human, SatoshiDICE's results are verifiable, thanks to cryptography, once the secret is released (the next day).
This can be verified without needing any software installed. Here's how:
So for your wagers from Jul 10, 2012 (UTC), get the secret from:
I run a provably fair casino - BitSaloon. I'd love feedback on how we can improve.
Random numbers are generated with sha256(salt + tx_hash) as a seed to Alea (an open source random number generator). If your generated number is less than or equal to the win percent, you get paid. All of this is verifiable by a user.
These games do not actually generate any Bitcoin. No Bitcoin is being mined in these games; that's not how Bitcoin works.
The Bitcoin comes from the service running the game. They are doing something other than running the game that is earning them Bitcoin. They then use that Bitcoin to give small amounts to their users. The Bitcoin is typically earned ...
Remember that the sender pays a fee.
That seems to be your problem. According to this info, if your transaction output is smaller than 0.01 BTC, you need to pay a minimum 0.0001 BTC transaction fee. Since you only have 0.00008 BTC, there are not enough funds to make the transaction (note also that the minimum fee is over 6x the amount you're trying to ...
Provably fair means the player can prove the operator didn't cheat. With website-based provably fair systems, the generation of a random number and/or client seed is easily to see and monitor. Unless a mobile app is open source, this same capability is not available.
So a provably fair website that provides an app doesn't mean the app provides provably ...
If you can afford storing the ~20GiB of blockchain on your disk, then bitcoind is a good bet. Otherwise, check out electrum, it has a very similar API, though there are some quirks. For the most lightweight solution, check out blockchain.info API, this should be the same API as bitcoind's.
The bitcoin software has it's own API.
Simply put, they run the bitcoind software and use RPC-JSON as the API.
EDIT : changed according to comment. Other implementations of Bitcoin also have their own APIs