Bitcoin Forum

I am confused as to why so many bitcoin gambling sites say "provably fair"

How do we prove an online game of luck is fair when we can't view the source code?  When they say you have a 50% chance of winning how do you know it is not really 10%? Maybe I am missing something here ???

As far as I'm aware, most of the 'provably fair' algorithms being used on majority of gambling sites work kinda like this:
1.) Casino server randomly shuffles the deck(s) of cards and takes a cryptographically provable hash using server-side generated seed.
2.) Casino then requests a randomly generated seed key from client-side application
3.) Server then takes this client-side randomly generated key and re-shuffles the deck in pre-deterministic (adding client seed and server seeds together for example) way such that the client side can subsequently verify initial seed (on server side) was indeed random when combined with newly generated client-side seed in newly shuffled deck.

http://www.provablyfairplay.com/blog/how-to-manually-verify-provably-fair-games.html

Maybe it will help you out :)

Honestly i don't believe in provably fair for some sites. but the only thing that i know that can give provably fair is sports betting.. or lottery. its randomly to choose if you are lucky you can win huge amount of bitcoin..
The other site has provably checker that you can check the seeds in your bet id to check if there's no fraud there.. but honestly we are just ordinary people we don't know the inside script or code of the games or if they are using python scripts its impossible to see what is in the code or inside  the script..
Well i just playing for fun not to make profit because i know i will lose my funds and i can afford to lose it..

Thats it you have MD5 hash before you play the game, and you can check the result of the exact MD5 hash with some windows program (google them as I don't remember them now) and the result should be the same.

playperfectmoneygames.com
playbitcoingames.com 

Are 2 small casinos at first, but really really rigid regarding MD5 hash and they truly are provably fair.

Thanks for the info guys. Most of the detail about cryptography went over my head but at least there's a way to prove it.

Yeah there is aways to prove if the site are giving a provably fair.. but not all gambling site are giving provably just always go to trust worthy gambling site.. and many site are giving provably fair and most of them are well known in this forum..

provably fair means that its the house edge of a gambling site and so no one can cheat it out or exploit it

You can find more details about Provably Fair Verification here :

Direct Dice (https://www.directbet.eu/Event.cshtml?EventID=777) - https://www.directbet.eu/Rules.cshtml#Dice

All-In Poker (https://www.directbet.eu/Poker.cshtml) - https://www.directbet.eu/Rules.cshtml#AllInPoker

Please feel free to contact us if you have any questions.

All the Best,

Michelle

https://www.DirectBet.eu (https://www.DirectBet.eu)

just try directbet.eu for sportsbet and fortunejack.com for other casino games, i play there and its very good and honest!

check out moneypot.com (http://moneypot.com)

Let me tell you that i have exactly the same concerns and doubts that you have...

In my experience i can tell you that safedice seems fair, i have not had any "strange" streaks with them ... there are sites that when playing with a 50% probability suddenly you get (after a short period of new bets) a streak of 20 losses in a row, after you´ve been winning for a couple of days...

if anyone of you can recommend us a dice site that you think is really fair please let us know...

I had loss streaks of 24 as well on safedice, those streaks are common when doing millions of rolls. Provably fair doesn't mean such streaks can't occure since all upcoming rolls has nothing to do with previous rolls even a 60 or 100 red streak on 49.75% would be possible.

It just means you can verify your bets and that the site can't alter the outcome.

But i like safedice best as a dicesite. :)

It's a bit complicated but you can prove it. The point is if a site says it's provably fair, you don't need every user to check. You just need one ;)

Yes I also think that provably fair in any gambling sites only a statement alone, many of the gambling site which gives the offer but in every game we are experiencing it less fair. But dunno whether this is true or not, because I do the gambling for pleasure

Though even provably fair can be manipulated sometimes when very cunning and devious website owners are involved.

provably fair ??? ??? yes i beleive but !!!!!
the important part of the games are:
1- the client seed (including your ip)
2- the number of nonce
3- the amount of your bet
4- the maximum daily amount of earning of the casino.(the most important)
so less you try your luck, more are your chances of winning, and do not stay more than 10 minutes in the same game because after this time there is no provably fair but the interest of casino.
exception: if you try your luck at the time when the casino makes its maximum profit you have the maximum chance of earning.

It seems you are very much confused about the idea of provably fair system. First, your client seed is set by you and has nothing to do with your IP. Also, I have never seen a provably fair site using the size of your bet and the profit you have on your site in the algorithm (feel free to name it if you do find one)

For the non tech savvy gamblers, they could use some easy-to-use third party verifiers such as the ones on https://dicesites.com/provably-fair to verify their bets. Having just a tiny tiny fraction of players or as you said just one player to actually verify the bets is not enough, as the sites could be selectively scamming without being noticed for a rather long period in that case.

this is an axample of provably fair system:
    Two strings are created :
    STRING1 = "[NONCE]:[SERVER SEED]:[NONCE]"
    STRING2 = "[NONCE]:[CLIENT SEED]:[NONCE]"
    For your last roll :
    STRING1 = "37363:1466894624-ep7cO7hO8QewxX39xrMaz2hKt5jDs8u6tBJaUwQ4DeUbAo89HeztbMQInt7b~RGj-197.113.31.194:37363"
    STRING2 = "37363:Nsnrkr3UB5SHMIGd:37363"
    Then HMAC-SHA512 is used to hash STRING1 with STRING2 as the secret key, giving us a 128 character hex string.
    The first 8 characters of the hex string are taken and converted to a decimal.
    This decimal is then divided by 429496.7295 and rounded off to the nearest whole number.
    This whole number is used as your roll, with the maximum possible value being 10,000.
can you explain me what do my ip in the NONCE ?
anoter STRING1 withe other ip: STRING1 = "37364:1466908679-Je1_Ep1mVm7Si9WPdgg0X7qNRJkFY07m.0x2NibLHdEHmu3TKgdnt.NJjc.eYTCc-154.242.209.177:37364"

if really the provalbly fair existe these site are ruined.

^ Is that site freebitco.in? I never used and never will use it to gamble my bitcoin (actually I never consider it as a gambling site but only a faucet), because it has a terribly high 5% house edge.
As shown in your above post, it seems the site uses your IP as part of the server seed but not the nonce (the nonce for that particular bet is 37363).

EDIT: I have created an account to do a little bit testing just now. It appears that the server seed hash (with my IP appends) does match with the server seed hash given before the bet. But still there is no reason to gamble there with such a high house edge. I would suggest you to try some proper dice sites.