<p>I run a provably fair casino - BitSaloon. I'd love feedback on how we can improve.</p>

<p><a href="http://www.bitsaloon.com/about/fair" rel="nofollow">http://www.bitsaloon.com/about/fair</a></p>

<p>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.</p>

CC BY-SA 3.0
2013-06-03T21:29:29.400Z
2013-06-03T21:29:29.400Z
Justin
<p><a href="http://www.libertybets.com" rel="nofollow">Liberty Bets</a> is also provably fair.</p>

CC BY-SA 3.0
2013-01-18T04:17:09.827Z
2013-05-18T01:03:02.410Z
2013-05-18T01:03:02.410Z
flaab
<p>The bitcoin casino site <a href="https://satoshibet.com" rel="nofollow">SatoshiBet</a> is 100% Provably Fair.
After each deal the player can manually verify the legitimacy of the shuffle.</p>

CC BY-SA 3.0
2013-08-08T12:09:16.120Z
2013-08-08T12:09:16.120Z
addi
<p><a href="https://www.bitoomba.com" rel="nofollow">Bitoomba Casino</a> supports provably fair or fairness verifications the site protected with SSL technology.</p>

CC BY-SA 3.0
2013-08-29T03:45:24.767Z
2013-08-29T03:45:24.767Z
Anderson Miller
<p>Also, <a href="http://doubledownbtc.com" rel="nofollow" title="DoubleDownBTC">DoubleDownBTC</a>, a Bitcoin Blackjack game, has a good explanation about provably fair gaming at <a href="https://doubledownbtc.com/fair" rel="nofollow">https://doubledownbtc.com/fair</a> </p>

<p>They implement one of the more popular Provably Fair models using a combined Server and Client seed to seed a shuffle on a deck of cards. They return the hash of the server seed before the player creates their seed so that the game can be verified afterwards.  They also have a popup "Verifier" which will do this live.</p>

CC BY-SA 3.0
2013-09-18T18:36:57.060Z
Hi Ryan! You mention this site in several answers. Is it your site? If it is you should probably disclose it. As you can see all your answers tend to get downvoted.
D.H.
CC BY-SA 3.0
2013-09-15T16:23:44.380Z
2013-09-15T16:23:44.380Z
Ryan Hall
<p>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.</p>

<ul>
<li><a href="http://www.BitLotto.com" rel="nofollow">http://www.BitLotto.com</a></li>
</ul>

<p>SatoshiDICE became a blockbuster (pun intended) method for online gambling.  It uses the transaction ID to determine the "lucky number" (between 0 and 65,535).  The secret used for determining that lucky number is revealed after the end of the day.</p>

<ul>
<li><a href="http://www.SatoshiDICE.com" rel="nofollow">http://www.SatoshiDICE.com</a></li>
</ul>

<p>bitZino gets credit for coining the term "provably fair", and first launched an online blackjack game then followed it up first with video poker and then roulette as well.  The game allows the user to change the client seed used for each play.</p>

<ul>
<li><a href="http://www.bitZino.com" rel="nofollow">http://www.bitZino.com</a></li>
</ul>

<p>BitJack21 was possibly the first.  The game gives the ability for the player to change the seed used for each hand.</p>

<ul>
<li><a href="http://bitjack21.com/" rel="nofollow">http://bitjack21.com/</a></li>
</ul>

<p>BitDice.com, SatoshiRoulette.com and others claim to be provably fair, I believe.  But I haven't gone through the verification steps myself to confirm.</p>

<p>BitLotto and SatoshiDICE wagers can be verified by anyone at any time after the results are published in BitLotto's instance, and after each day's secret is published for SatsoshiDICE's instance.  Proving that bitZino always computed the results correctly requires logging of the hash, the client seed, and also the way the hand was played -- so it is much more effort to verify unless there is automation but no automated solutions for verifying all wagers on bitZino have been made available.</p>

<p>Here's an article on what provably fair means:</p>

<ul>
<li><a href="http://www.forbes.com/sites/jonmatonis/2012/08/31/bitzino-and-the-dawn-of-provably-fair-casino-gaming" rel="nofollow">http://www.forbes.com/sites/jonmatonis/2012/08/31/bitzino-and-the-dawn-of-provably-fair-casino-gaming</a></li>
</ul>

<p>Here is one explaining how it works:</p>

<ul>
<li><a href="http://bitcoinreviewer.com/provably-fair/" rel="nofollow">http://bitcoinreviewer.com/provably-fair/</a></li>
</ul>

<p>[<strong><em>*</em>**<em>*</em>**<em>*</em>**</strong></p>

<p>Additional sites in which claim to be provably fair but I've not gone to verify:</p>

<ul>
<li><a href="http://www.satoshibet.com" rel="nofollow">http://www.satoshibet.com</a></li>
<li><a href="http://www.BitMillions.com" rel="nofollow">http://www.BitMillions.com</a>  (Apparently uses as a seed a Twitter sequence?)</li>
<li><a href="http://www.KingCo.in" rel="nofollow">http://www.KingCo.in</a> </li>
<li><a href="http://www.BitcoinVideoCasino.com" rel="nofollow">http://www.BitcoinVideoCasino.com</a> </li>
<li><a href="http://www.Playt.in" rel="nofollow">http://www.Playt.in</a></li>
<li><a href="http://www.bitino.com" rel="nofollow">http://www.bitino.com</a></li>
<li><a href="http://www.pinballcoin.com" rel="nofollow">http://www.pinballcoin.com</a></li>
<li><a href="http://www.blockchainroulette.com" rel="nofollow">http://www.blockchainroulette.com</a></li>
<li><a href="http://www.diceoncrack.com" rel="nofollow">http://www.diceoncrack.com</a>   (Uses transaction hash just like SatoshiDICE, so should be easily to verify)</li>
</ul>

<p><em><strong></em>**<em>*</em>**<em>*</em>***</strong>]</p>

CC BY-SA 3.0
2013-03-15T17:02:41.787Z
I just rejected a proposed anonymous edit for "bit millions".  They say provably fair, but the random seed comes from a twitter account they may control.  I couldn't easily prove otherwise.
makerofthings7
CC BY-SA 3.0
2012-09-29T08:44:14.803Z
If I missed any, I'll add them, just let me know.
Stephen Gornick
CC BY-SA 3.0
2012-09-28T23:25:04.353Z
2014-01-16T16:47:16.770Z
2014-01-16T16:47:16.770Z
Stephen Gornick
<p>Through the spread of Bitcoin for the purposes of online gambling, the concept of "provably fair" games came more into the limelight. Which of the Bitcoin-powered gambling websites are provably fair?</p>

<p>For clarity's sake, a provably fair game is a game that uses cryptographic algorithms to ensure their players that the game host or other players did not temper with the outcome of the game after it has begun.</p>

<websites><cryptography><gambling><gaming>
Which Bitcoin-powered gambling sites are "provably fair"?
ThePiachu
# Which Bitcoin-powered gambling sites are "provably fair"?

(Asked by: username_0 on 2012-09-28)

Through the spread of Bitcoin for the purposes of online gambling, the concept of "provably fair" games came more into the limelight. Which of the Bitcoin-powered gambling websites are provably fair?

For clarity's sake, a provably fair game is a game that uses cryptographic algorithms to ensure their players that the game host or other players did not temper with the outcome of the game after it has begun.

**Tags:** websites, cryptography, gambling, gaming


---

## 6 answers

### Answer by username_7 on 2012-09-28. Score: 11 | Accepted answer

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.

* <http://www.BitLotto.com>

SatoshiDICE became a blockbuster (pun intended) method for online gambling. It uses the transaction ID to determine the "lucky number" (between 0 and 65,535). The secret used for determining that lucky number is revealed after the end of the day.

* <http://www.SatoshiDICE.com>

bitZino gets credit for coining the term "provably fair", and first launched an online blackjack game then followed it up first with video poker and then roulette as well. The game allows the user to change the client seed used for each play.

* <http://www.bitZino.com>

BitJack21 was possibly the first. The game gives the ability for the player to change the seed used for each hand.

* <http://bitjack21.com/>

BitDice.com, SatoshiRoulette.com and others claim to be provably fair, I believe. But I haven't gone through the verification steps myself to confirm.

BitLotto and SatoshiDICE wagers can be verified by anyone at any time after the results are published in BitLotto's instance, and after each day's secret is published for SatsoshiDICE's instance. Proving that bitZino always computed the results correctly requires logging of the hash, the client seed, and also the way the hand was played -- so it is much more effort to verify unless there is automation but no automated solutions for verifying all wagers on bitZino have been made available.

Here's an article on what provably fair means:

* <http://www.forbes.com/sites/jonmatonis/2012/08/31/bitzino-and-the-dawn-of-provably-fair-casino-gaming>

Here is one explaining how it works:

* <http://bitcoinreviewer.com/provably-fair/>

[***\**\*\**\**\*\**\**\*\***

Additional sites in which claim to be provably fair but I've not gone to verify:

* <http://www.satoshibet.com>
* <http://www.BitMillions.com> (Apparently uses as a seed a Twitter sequence?)
* <http://www.KingCo.in>
* <http://www.BitcoinVideoCasino.com>
* <http://www.Playt.in>
* <http://www.bitino.com>
* <http://www.pinballcoin.com>
* <http://www.blockchainroulette.com>
* <http://www.diceoncrack.com> (Uses transaction hash just like SatoshiDICE, so should be easily to verify)

\*\**\**\*\**\**\*\*\*]

> **Comments:**
> **username_7**: If I missed any, I'll add them, just let me know.  
> **username_8**: I just rejected a proposed anonymous edit for "bit millions".  They say provably fair, but the random seed comes from a twitter account they may control.  I couldn't easily prove otherwise.  

---

### Answer by username_1 on 2013-06-03. Score: 2

I run a provably fair casino - BitSaloon. I'd love feedback on how we can improve.

<http://www.bitsaloon.com/about/fair>

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.


---

### Answer by username_2 on 2013-01-18. Score: 1

[Liberty Bets](http://www.libertybets.com) is also provably fair.


---

### Answer by username_3 on 2013-08-08. Score: 0

The bitcoin casino site [SatoshiBet](https://satoshibet.com) is 100% Provably Fair.
After each deal the player can manually verify the legitimacy of the shuffle.


---

### Answer by username_4 on 2013-08-29. Score: 0

[Bitoomba Casino](https://www.bitoomba.com) supports provably fair or fairness verifications the site protected with SSL technology.


---

### Answer by username_5 on 2013-09-15. Score: 0

Also, [DoubleDownBTC](http://doubledownbtc.com "DoubleDownBTC"), a Bitcoin Blackjack game, has a good explanation about provably fair gaming at <https://doubledownbtc.com/fair>

They implement one of the more popular Provably Fair models using a combined Server and Client seed to seed a shuffle on a deck of cards. They return the hash of the server seed before the player creates their seed so that the game can be verified afterwards. They also have a popup "Verifier" which will do this live.

> **Comments:**
> **username_6**: Hi Ryan! You mention this site in several answers. Is it your site? If it is you should probably disclose it. As you can see all your answers tend to get downvoted.  

---

