Topic: Lowest unique number [JUNE 2013] [PROVABLY FAIR] *UPDATE JUNE 9, PLEASE COMMENT* (Read 1497 times)

game sounds interesting.
I still read-read the other reviews,
and really want to play this game

hm, my bad, I misread, sorry   I do have 0.1 BTC, holding it for security purposes.

No I meant the other way around. This thread is still live, the other has ended. You have the funds for this one!

I no longer hold any funds for this.  This thread should be marked as closed until the OP decides to re-open it again.


The 0.1 BTC funds I was holding will now be used for this purpose: https://bitcointalksearch.org/topic/closed-648439

Edit: It was the other way around, I have 0.1 BTC, sent by kuverty, will be holding on for security purposes only.  For this thread.

Why not try it out then 

In my opinion, this game is already pretty fair.  The OP cannot run away with the funds, as for he as an escrow (me).  He has also deposited extra BTC as security.  It's also provably fair.  How much more fair do you expect it to be?

game looks interesting......

Can you see any problem with this arrangement?

yeah creating fair game is important,  I usually wont participate in a game that is not fair, lets come together and think of a way to help the OP improvise.

Any feedback appreciated and welcome everyone who wants to play.

I revised the rules and made them more clear to attract more players. If you feel that the game has a significant flaw for you, please speak out! I want to create a fair game for all.

Thank you.

Thanks, it is much appreciated!

I also edited the original post for some clarity and I do feel the game is vary fair now. It indeed is provably fair if everyone decides to keep their exact numbers secret until the end, but it is not a problem if not. I think the biggest bets would be hashed anyway.

This game sounds fun.. I'm going to keep an eye on it

It is fair now, isn't it? Well, I can not rule out the possibility that I might cheat by looking at the plaintext bets but I want to continue this and keep this exciting and more importantly (I think), most bets will be hashed.

So you just select how many numbers you want, pay the amount of mBTC and post you numbers here in the thread - SHA256 hashed with a secret string only you know. Then at the end of the round, when no new participants are let in, you reveal the string that contains your numbers and produces the pre-published hash.

yeah its a great idea, doing so I might invest my coins to try to win some, when you think you will create a fair system?

Anyone in?

You can use this website to calculate the hash: http://www.xorbin.com/tools/sha256-hash-calculator

Hash a string that contains your numbers and some secret password (not any password you use elsewhere), in an unambiguous manner, then post your hash here and you are in - check the rules.

That's a good idea!  The website could do the hashing client-side, using a client-side randomly generated seed.

Or see https://lbaat.net/ , particularly the ability to "Send message to the future".  I guess that just moves the trust from you to them (the people running lbaat can read the messages ahead of time), however.


You can keep the secret in the browser's local storage, and have a button to "reveal guesses" or something which sends the cached secret to the secret.  That hashing itself needn't be done by the user, just by his browser.  This is the same kind of trust the blockchain.info wallet has - you trust its client-side javascript to know your private key and not to share it unencrypted with the central server.

For a forum game, the players are going to have to do the hashing and secret-caching themselves.  But the kinds of people wanting to play such a geeky game are probably capable of that if you link them to a site that does sha256 for them...

Yes, provable fairness seems like a pretty much impossible thing to achieve with this type of a game. I guess a site could be possible anyway, but it would have to be built up slowly. If it is running properly, it would make no sense to cheat for a quick buck.

Well, it could be provably fair if users paid and provided only salted hashes to whomever runs the game, then they would have a set time to reveal their inputs in order to claim their winnings. Preferably everyone should publish the hashes then, or at least the non-hashed bets should be published before hash-using players publish their numbers in plaintext.
But that lends quite a bit of responsibility to the players, it should be doable anyway though. At least it can be done with this forum game.
Also I can now actually see this game working as a gambling site, too. Maybe sacrificing a little usability in favor of provable fairness is OK, not everyone needs to use hashes and the bitcoin crowd is generally pretty techy.

So, instead sending me the numbers you can pay and send me a SHA-512 hash of a string such as "1, 3, 10-14 entersomerandomstuffhere9quy4" or just publish the hash in a message, which is probably the easiest.

Dooglus, what do you think? Sorry for the confusing, stream-of-thought post.

As I said in the JD chat where you mentioned it, the biggest problem with this kind of a game is that somebody (presumably but not necessarily you) gets to see all the entries early, and can use that information to win.

I don't see how such a game can be made provably fair, which might make it difficult to get people to play.

Done! I'll just send you the PM, july 1st is correct.

Alright, the post has been edited. PM me or post here the address you want the funds sent back to you on.. July 1st, right?
Also, you should add that you accept escrow in the OP

That will be for security only, thank you for the confirmation. It's just there to start the game off.

Also, I'll confirm once I receive the 100 mBTC...  What do you want me to do with it?  Will it be the start of the prize fund, or will it be just as a collateral/security?  Should I add it to the prize fund or send it back to you once the "game" is over?

Edit: funds have been received.  https://blockchain.info/tx/f168b6af2736d262de18d30da2e295c27279a5223d28792bb43c732fae6dc5ca  99 mBTC will be returned to kuverty's provided address. 1% will be kept as an escrow fee.  This payment is for security purposes only.

I have not yet received it, nor have I seen any unconfirmed transaction.
Did you send to this wallet? 1Q2CupiU5DfWupRGBQ66QYRqvxoNxGZCcn

Thank you for accepting escrow, PM me the terms and stuff

Only my word. I could use you as a trusted escrow. 20 % sounds steep but there's only one winner and the fee is deducted only from the losers' bids, so you get a nice return. There is some trouble involved running this and personally I think 80 % of other people's bids plus your money back is a nice amount to win.

Anyway, I would not want to lose a two year old account, I'm not planning to go away from Bitcoin. Why would anyone, at this point...

EDIT: I have just sent 100 mBTC to monbux, he can hold them in escrow. Further bets will go to him, too. The transaction is not yet visible but will be soon, monbux will surely confirm this soon. Happy betting all!

Please use monbux as escrow, or maidak

Alright, so it sounds like a pretty interesting game!  Might be a bit of work for you...
Also, a 20% fee?
Lastly, would you mind if I escrow this for you?  What guarantee do you have of paying back?

Thanks a lot!

reserved for stats

0 numbers reserved as of June 4th

Game started on June 4th

As I like the concept, here is an unique bid auction (with ESCROW and provable fairness!).

The rules are as follows:

You reserve as many numbers as you want to, any positive integer will do (1, 2, 3, 4... and so on). Reserving each number costs 1 mBTC (0.001 BTC). You can even reserve the first 1000 integers if you wish, at the cost of 1 BTC.

Make the payment and send me the numbers you wish to reserve. Just pay me for as many numbers as you'd like and send me a list of numbers, such as "1, 2, 3, 9, 10, 12". If you have doubts regarding fairness, you may instead of giving me the numbers, just create a SHA-256 hash of a string with the numbers you chose and a password-like part at the end, that only you know. Then, after I have published all the results, those who sent hashed numbers will reveal their numbers. For the secret part, do not use an actual password as you must publish it. This is not easy, but makes the game provably fair as I, or nobody else, will be able to tell the hashed numbers before the game ends.

Trying to cheat by editing you message with the hash to a winning one after the game ends will not work, so please do not try.

But when doing this, please pay attention: you must be able to give the proper string for others to verify it gives the correct numbers. You must also take responsibility for paying the correct amount. If you paid for n tickets but have more in your list, only the n smallest will be counted. Refunds can not be given as this would enable cheating. So please, make sure you can replicate the hash.
Those who publish hashes, will have three days to publish their secret string after I have published the non-hashed bets for all. After that period, you can not claim your winnings any more. Everyone who publishes hashes will be notified by private messages, when the three-day period starts.

The person who has reserved the smallest number that no one else has reserved, gets his money back and wins 80 % of the money others have put in the game.

Game will end on the last minute on June, UTC+0. After that there is one day left to send any numbers that have already been paid for and then I will publish the results for non-hashed numbers. After that, there is a three-day period to wait for the hashed string submitters reveal their strings. Stats will be published on the number of reservations while the game is still on; I think this makes the game more interesting.

Just send me a message with the numbers you want and I will send you the address where you can pay. If you have any questions, ask them and I will update the post under this one, that has all the stats.

As for me, well, I'm an old member as you can see, I've been on the forums for more than two years now and I have no intention to scam anyones money. I can also reveal my real-world identity to some trusted member who asks for it. Edit: I accept escrow, a trusted escrow with the nick monbux will handle it.

In short

1. Decide on the numbers you want to get
2. Decide, whether you will trust the privacy of the private message system and my honesty
 2.1 If you choose to trust, ask me for a payment address and after paying send me the numbers
 2.2 If you want to be cautious, ask me for a payment address but instead of sending me the numbers, publish in this thread the SHA-256 hash of a string that contains
       your numbers unambiguously, including a secret password-like part. Be sure to come back to reveal the string! I will PM you about it.
3. Read and understand the rules and wait for the results!

Why is it fair?

The game is fair because of the hashed numbers. They are published ahead of time and they are here for all to see. I can not know what they contain, nor does anyone else but the person who sent them in. Also, they can not spoof the bets - creating a known SHA-256 digest (hash) from a string that was not the original one would be an almost miraculous feat and if someone could do that, they would have better applications that cheating here. It is secure. I expect that the majority of the bets will be hashed, so that knowing the plaintext bets give less of an edge (that I would still not use in any case).

So, everyone's bets will be secure until the round is over. The game is simply closed after that. The unhashed bets will be published after the game closes but before the most crucial, hashed bets are revealed. I can't manipulate the result at that point when everything is public, nor can anyone else. If anyone wanting to participate feels this is inadequate, please reply to this thread and tell me.

Have fun you all and win big! If you notice flaws in the system, please let me know.