Bitcoin Forum

I'm finally done with a small project and curious if anyone wants to try it out or give me some feedback on it.

http://BTCKeno.com (http://BTCKeno.com)

There is also a testnet setup for the site at http://testnet.BTCKeno.com (http://testnet.BTCKeno.com) if you want to try it out. Same site, same code, etc. just on the bitcoin testnet. As far as I am aware of, this is the only site that has a testnet version.

What is Keno?
Keno is a game where you select up to 15 numbers. The computer will select 20 numbers, and you are paid based on how many of those that you both select. The pay table contains a multiplier so whatever your bet amount is, it is multiplied by that.

What is BTC Keno?
With this site you can select up to 15 numbers. You also enter in your payout address. Once you submit your ticket, you are given a unique address where you send your bet. Once you bet has been confirmed (6+ confirmations) you are sent your winnings to the payout address you listed. Also once you submit your ticket you are given a unique URL to check the status of that ticket.

Is this provably fair?
Yes, you can check out the code used to generate the random numbers at https://gist.github.com/4516159 and you can find the daily secret keys at http://btckeno.com/keys (they one that is in current use is not shown until a new key is generated). The keys are generated daily.


I'm working on a few new features/improvements for the site, so I'm open to any and all suggestions you guys have.

Thanks and enjoy.

1 confirmation would be enough IMHO.

Seems like I could do that. I'll push up some updates later tonight and lower that, or at least lower it on the testnet version.

Updated so that only 1 confirmations is now required, this has been updated on both the testnet site and the production site.

I made a wager for 1 BTC and won 2 BTC.  It's been about 20 minutes since it confirmed 6 times (and my winnings were announced) but I still haven't received my 2 BTC.  Unfortunately I closed the window and lost the URL because I figured it wasn't needed any longer.

Interesting. Please make your site provably fair. There is no excuse why not to today

I see that in the database, I'm updating the site right now (stats page will come up next). The reason it hasn't paid out yet is because there is not enough funds in the account to pay you yet. I'm transferring all that I have and trying to get some more so you will get paid. I apologize about that and I will make sure that it is being taken care of.

Details: http://btckeno.com/e57052a2a3512d000241543b4cf1fa9b10b86b6b741c29278a548f848345fc1ef5b25543fc02f5744c87d4219f42a97bd2869611660b72145ae8a45f69e788c4

And yes, I do believe in full transparency and will be getting more updates to you soon on this. Again I apologize.

Update

Can now search for your tickets based off of payout address http://btckeno.com/search

Update

https://blockchain.info/tx-index/42546202/372582f6929c4be3cd08013ad4ba1fe16be2d1ed8854bbfa4a423402885d0f40

Paid =)

Please keep this URL as this is the only way to track your game.
Bet Amount   1.000000000
Confirmations   3
Bet txid   87dbbb666e2e9899506efa283148dd73f1c66b2a74eb6cd809a38aa945f81fcf
Amount Won   Have not yet confirmed your bet.
Paid out at   Have not yet confirmed your bet.

Thought it was 1 confirmations?

Free web design advice: Bet txid is pushing the width of the seven columns container. Wrap the txid in <small> tags so it's less OCD inducing :)

Thanks, but it concerns me that you had to scramble to find the 2 BTC to pay me!  What if someone won a few hundred BTC (your top jackpot is 10,000 BTC) ??

The task that checks has been updated to payout at 1 confirmation, until it pays out, it will keep updating the meta data.

That is a good question. To be honest, I have no idea how I will come up with it, but I can will guarantee you that they will get paid.

Done, just finished the deploy. Good catch on that, I'm a horrible at frontend design. I think the entire frontend looks like ass. Trying to find a frontend designer around town. Have talked to a few, but no one worth it so far.

< gestures towards userbox  ;)

I think that if you won 10,000 BTC, the site is going to disappear. Especially if it was just up.

Nope, if someone won 10K in BTC, I would have to suck it up and send them out. That would be shitty luck on my part. There are a lot of various services that I want to push out, so if screw this up, it would be hard to start over again.

Can someone send me some testnet coins?
mvys758KaKLTFmh9gRdXnequBksKb4C4xD

I've mined a few so I can return them when they mature

 ??? ??? ??? ::) ::) ::) ??? ??? ???

What could possibly go wrong? 

And no, as we've seen in the past, it would not be hard at all to start over again.  It's happened all the time.

I too lazy to try it again, I want my customers to be very well taken care of.  ;D

Pay tables have been updated, check out the about page for the most recent.

http://btckeno.com/about (http://btckeno.com/about)

The update I'd like to see is any evidence you can actually pay out the bets on this paytable, as you've already admitted you can't and would be scrambling if anyone hit one of them.  When you're willing to take bets for these amounts that you don't have on hand, that's scammy to say the least.

How do you want me to prove this? The reason that the previous customer did not get paid in a timely fashion is because I made a choice not to keep a large amount on the server for security concerns. I could have made up some excuse, but instead I was honest and got that customer their money as fast as I could. Which was just sending more BTC to the server. If you want me to make an excuse I can, but I feel honesty is the best.

The bet in question is (which you are talking about) is http://btckeno.com/d79fd7a0c960705e958686764c30b789477d8a09ea677be63aa966aba3cc9a5e39f3f591e2890a016e88bd67b7b9d0fe28812e394eee314eb1aec75def099e1a and there is the bet txid and the payout txid on that page which you can find info https://blockchain.info/tx-index/42540538/87dbbb666e2e9899506efa283148dd73f1c66b2a74eb6cd809a38aa945f81fcf and https://blockchain.info/tx-index/42546202/372582f6929c4be3cd08013ad4ba1fe16be2d1ed8854bbfa4a423402885d0f40 with a time of ~25 minutes from bet to payout. I think that is more than plenty of time, if that's not acceptable, let me know and I will come up with a faster way to get payouts to customers.

I do realize that the community has been screwed in the past, and that this "new gambling site" has to prove that it's honest and that's one of the reasons I've published my github and personal web site urls. I know that means shit to most people, but in my opinion I think it shows I'm at least a little creditable. If you try hard enough, it's not hard to find out who am and where I am at. So what evidence do you purpose I show to everyone? I want this site to be a success, so let me know what you need.

FYI the bet I placed earlier is still at 5 confirms for some reason, and I can't see what number satoshi picked.

Is this game provably fair?

Shoot me the url and I will look into it, when I updated the confirmations from 6 to 1, there are a few places where I missed the checks on that page. I will check it out for you.

That's a good question and one I'm trying to figure out. I can post you the code I am using as a random number generator, other than that I'm not sure what else I can do. I am working on a stats page that will list wins/losses and the amounts. If someone wanted to scrap that data and parse it, they could see if there was a statistical error that should not be there. However there is not yet enough data.

Do it like BTCMultiplier. If you select the number 1 and 2, there's one address and just one address. Winnings are sent back to the address it came from. Have a daily secret, publish a hash of them in advance, and then hash secret + txid. Get the first few bytes, use that to determine what numbers satoshi picked.

The issue is I don't want to send it back to the address that sent the bet. I'd like the user to put in the address that they want the payout sent to. As of right now here's more or less the flow.

User comes to site, submits numbers and an address to send payout.
Bet is received and the satoshi picks are selected and then counts what it matched
Once bet has been confirmed, payout is sent to the payout address

If anyone has suggestions or can point me to more resources, I'd be more than happy to set something up. BTW I like how BTCMultiplier has a list of bets on their front page. I want to add something similar. I'll have more time Friday evening to push updates.

Thanks

OK, to make it provably fair then:

$serverSecret = hash("sha256", rand());
$serverSecretHash = hash($serverSecret);
//store serverSecret somewhere
echo $serverSecretHash;

function process_keno($tx){
$result = hash("sha256", $serverSecret . $tx['txid']);
$dec = hexdec($result);
mt_srand($dec);
$generated = [];
for($i = 0; $i < 20; $i++){
$num = mt_rand(1,80);
$generated[] = $num;
}
return $num;
}

Anyone (with a copy of PHP) will be able to verify that you are generating the correct results, but they will not be able to predict the results ahead of time.

For more info, go to satoshiDICE and click on the Verification tab (or type in "javascript:$('.verificationbox').slideToggle();" in the address bar on Chrome), see BitZino's https://bitzino.com/about/fair, http://btcmultiplier.com/keys.php?l=en

The issue I see with that code is it pulls the 20 numbers with replacement. Needs to be without replacement :P The other issue is according to php.net's notes on mt_rand and rand, they do "not generate cryptographically secure values".

I get your point that it needs to be proven to be fair, and I'll figure out a way to make it so. I'll take this weekend to push up an update that is based off some of that code are create some scripts to show that it can be proven fair.

Thanks for the input

I agree, you should not use any kind of random function to generate the game values -- there's plenty of entropy in just the txid+secret combination (the secret can be whatever length you want).  Besides, your users will need a deterministic way to prove to themselves that the game is fair -- just like the other sites.

Got it, I'll make some updates over the weekend and do a deploy with an algo that uses the transaction id of the bet to generate 20 random numbers. Thanks guys, I'll get something awesome up and running soon.

Yep, I just some some simple code for the purpose of illustrating what I'm saying  :) which is why I linked to more info.

Are you serious that you don't know how to prove you have a certain amount of BTC?


I agree, but you've basically admitted that you don't have enough BTC on hand to pay out some of the bets on your paytable, and admitted you don't even know how you'd acquire them if someone won them.  This was your previous response.


It is a serious problem to take bets you can't cover.  Nobody legit does that.  It may just be cluelessness, but if not, it is frankly scammy.  If you are spreading gambling games, as the house, it is simply not kosher to ask people to accept your marker if they win.

@darkmule
The issue with not having enough to payout has been resolved, I have updated some of the settings so that there will be more btc left on the server. If there was ever a need to have more I would send them to the server via my personal wallet. If that still will not cover the bet, I will just jump on mtgox and purchase enough to cover the bet.

I also agree that people shouldn't accept that "oh, you'll get paid whenever". I want my customers to be paid ASAP, ie as soon as I can confirm the bet.

I have a few updates that I will be pushing up soon, the updates are already on testnet.btckeno.com

Thanks
-Joshua

UPDATES

* Payout table has been updated with decreased payout amounts (min bet is 0.01 BTC, max bet is 1 BTC, I'll update this later to allow larger bets)
* Bets can now be proven fair and details can be found on the about page along with a link to the code gist that is used. (This code will update at a later point in time to include a daily secret key, but for right now, it doesn't seem like I should require one)

If you have any questions/comments/suggestions, please feel free.

Thanks,
-Joshua

it doesn't seem like I should require one ??

Are you waiting to get your wallet plundered? :P

looks like you didn't check the probabilities.

you should adjust your payouts because:

if I play only one number, my expected return is 0.3 times the bet
if I play 13 numbers, my expected return is 0.986163742250369 times the bet

and your house edge is almost 30%, this is too much for a bitcoin gambling site.

Please pay out the following:
http://btckeno.com/36267762729d1bfb625267931b7557abfba14f71365ece523924724ea6710f66c5827533c902394f1999aa8a462fd10c0fa6cf24cd71e36f26961ea08314bbcb
http://btckeno.com/91dfc6cff8ffed8924d4a108818b9a43f69fff2e9f6c7aa083f3e2c89a05ceaab4b1d1b32f66666291374f9e5d51441a2a9891520a482e40974b773f5b55c735

EDIT: I wonder how I screwed up a bet that should have won 2x :/

Updates

• Updated the site so it now uses secret keys when calculating the random numbers. You can see the keys at http://btckeno.com/keys and the code that generates the random numbers at https://gist.github.com/4516159 The picks are generated by the bet transaction id and the secret key that is used is the one that is current for that day when the bet comes in.

Future/Planned Updates

• Display the most recent winners/losers on homepage
• Update pay table
• Increase the max bet

Most of the major issues that everyone seems to have had are now updated and fixed. I will continue working on the site and post updates here every now and again. As always suggestions are welcome.

Updates

Sorry I have not posted any updates in awhile, there have been a few personal issues. Just want everyone to know that I'm still here  ;D

• Homepage now lists previous 10 tickets

In the coming few weeks I plan on updating the site with a lot of new features. Also plan on sitting down and tweeking the payout table to spit out better returns for clients. Also plan on spitting out some paytable stats soon as well. It will a prettier version of this:


And will also list all of the expected returns. The above assumes you bet the max of 1 BTC and only picked one number. This should address


I am also open to any other comments and suggestions that people have. I also plan on having some quick pick buttons, click the "Pick 5" button and 5 numbers get randomly picked for you.

There may also be a need for me to pre-populate the payout address field to the last one you used?

Any other data you guys would like to see about the numbers, let me know.

Thanks
-Joshua

Updates

• Updated the homepage to have "Quick Picks", you pick the number and it will randomly select that amount.
• Payout Table Update - I have only updated the one pick, see below for the payout rate, other numbers remain the same, I'll get around to updating those a little later. Pick one number for a 95% expected return =)

Prize = Multiplier, ie (bet amount * multipier), bet amounts MUST be between 0.01 BTC and 1 BTC.


Have fun guys, I already see a few people using this a lot ;p I'm always open to comments/suggestions to improve the site.

Updates Feb 14, 2013

• Increased payout for one picks
• Updated the homepage a little
• View your odds in json - http://btckeno.com/odds (http://btckeno.com/odds)

Added a page that will list your odds based on the amount of numbers you want to pick. By default it will display the odds for if you select 15 numbers. It gives the odds for each hit. So to read it, if you pick 15 numbers, the probability that you will get X hits is... The prize is your multiplier, so if you bet 1 BTC, multiply that by the multiplier to get your amount won.

Here are links to all odds for all valid picks.

http://btckeno.com/odds?picks=1 (http://btckeno.com/odds?picks=1)
http://btckeno.com/odds?picks=2 (http://btckeno.com/odds?picks=2)
http://btckeno.com/odds?picks=3 (http://btckeno.com/odds?picks=3)
http://btckeno.com/odds?picks=4 (http://btckeno.com/odds?picks=4)
http://btckeno.com/odds?picks=5 (http://btckeno.com/odds?picks=5)
http://btckeno.com/odds?picks=6 (http://btckeno.com/odds?picks=6)
http://btckeno.com/odds?picks=7 (http://btckeno.com/odds?picks=7)
http://btckeno.com/odds?picks=8 (http://btckeno.com/odds?picks=8)
http://btckeno.com/odds?picks=9 (http://btckeno.com/odds?picks=9)
http://btckeno.com/odds?picks=10 (http://btckeno.com/odds?picks=10)
http://btckeno.com/odds?picks=11 (http://btckeno.com/odds?picks=11)
http://btckeno.com/odds?picks=12 (http://btckeno.com/odds?picks=12)
http://btckeno.com/odds?picks=13 (http://btckeno.com/odds?picks=13)
http://btckeno.com/odds?picks=14 (http://btckeno.com/odds?picks=14)
http://btckeno.com/odds?picks=15 (http://btckeno.com/odds?picks=15)

NOTE: This url will stay valid, however I am planning on cleaning up the page to so default response will be just a plan HTML page.

Future updates to the payout table will include decreased expected return for some of the picks. A one pick game will always contain your best odds. The others will just be for shits and giggles, I see no point in having a keno game if the expected rate of return is constant for every outcome.

As always, feel free to post a reply or PM me if you have any suggestions/ideas/complaints and I will take care of them.

really? Why not? The reason the players play with more numbers is to have a chance of winning more with the same bet value.

So if I pick 1 number, my expected return is 97.5%. If I pick say 4 numbers, each number has it's own expected return. So if I was to make everything have a constant expected return, what's the point in submitting a ticket with 1 number or 15?

with your odds, when playing with 1 number you have 25% odds of winning 3.9 and only 3.9
but when playing lets say with this paytable for the 13 numbers:

0-0
1-0
2-0
3-0.5
4-1
5-2
6-4
7-8
8-23
9-80
10-220
11-620
12-2670
13-6000

you have will more than 41% of getting between your ticket back and 6000 times your bet. for sure I will bet with 13 numbers.

The problem is that you're dealing with human nature. If I will gamble my money, so I wanna have a chance, even if it is insignificant, of multiplying it by thousands.

Take the satoshidice statistical analysis by dooglus https://bitcointalk.org/index.php?topic=80312

number of bets of "less than 2": 4326
number of bets of "less than 1": 84807

we have two times the chance of hitting the "less than 1" with the "less than 2" and when hitting the less than 2 my money will be multiplied by 32000. but the people choose to cut the chances by the half to have a chance of winning 64000x.

I already have a confirmation

though it says it hasn't confirmed, nor
that it has received it.

Is this script automatic or manual?
:I