999dice.com - How to prove their fairness?

[iluvbitcoins]

I'm kind of new to verifying bets and their fairness
I've seen 999dice and I know about their history and everything, but 0.1% is a REALLY low edge

This is what their website says

Bets are guaranteed to be fair because the seeds for the bet are known before you bet.

The formula is

Server Seed + Client Seed (->byte[4]) + Bet Number (->byte[4])
Double SHA2-512 hash the result
Keep taking groups of 3 bytes and converting to an integer, until a value less than 16 million is found. If you run out of bytes, hash it again and start over.
Find the value's modulus of 1 million
The modulus is the bet result!
You are given the server seed's hash. Once the bet has been placed, the server seed is available, and you can verify the fairness of the bet. For automated bets, all bets are made using the same server seed.

The current server seed hash is c49a6430d7d5d34a8b084186b50bc4a34a56bcd1b30475d2b8816871640fa4e7

So, how exactly do I verify if a bet is fair?

What I need is
1. Server seed - check
2. Client seed - check
3. Bet Number - check

Double SHA2-512 hash the result

SHA2-512, urghh, does that mean I'm supposed to hash the result of the bet as in 233699 twice on SHA512, what's Double SHA2-512

Keep taking groups of 3 bytes and converting to an integer, until a value less than 16 million is found. If you run out of bytes, hash it again and start over.
Find the value's modulus of 1 million
The modulus is the bet result!

Aaaand, I'm lost.

[kidsuzudn]

Check all their seed in the bet that you want to clearly it's fair. 999dice is good one with low edge so i guess let try another time with your luck ok?

[iluvbitcoins]

Check all their seed in the bet that you want to clearly it's fair. 999dice is good one with low edge so i guess let try another time with your luck ok?

https://bitcointalk.org/index.php?topic=948965

https://bitcointalk.org/index.php?action=profile;u=185799

Not exactly I'd take their word on it.

[iluvbitcoins]

I've tried verifying it with DiceBot
Are they scamming or am I doing something wrong?
Believe it's the other one  

http://prntscr.com/gjuz1m



What I get in Dicebot is

betnumber,luckynumber,,Please note, This algorithm is still in testing, some Numbers Might be wrong.
,,,Check the alternative roll verifier
1,46.9725

While the actual roll was [861167]

I thought maybe I'm an idiot and I need the new client seed with the old hash, still a wrong result o.o

[Bitfort]

I'm not speacialist as well but something is shady here for sure.

Have to note the standard procedure (for similar sites) is that the server seed is given (and not changing) for e.g entire one day. And published next day (and changed of course) so you can verify only bets made day before.

I have tried one thing (which if found quite interesting) in above mentioned post ....  and found the server seed is indeed changing for every bet.

This would not be totaly unfair as long as there would be any way to check fairness of this seed generation (I did not find on which basis this seed generated). So basicaly the admin disguise the fairness into two levels but we have options to check only the first level ...and no clue how to verify the second one ... aka NOT PROVABLY FAIR. My humble opinion.

[iluvbitcoins]

I'm not speacialist as well but something is shady here for sure.

Have to note the standard procedure (for similar sites) is that the server seed is given (and not changing) for e.g entire one day. And published next day (and changed of course) so you can verify only bets made day before.

I have tried one thing (which if found quite interesting) in above mentioned post ....  and found the server seed is indeed changing for every bet.

This would not be totaly unfair as long as there would be any way to check fairness of this seed generation (I did not find on which basis this seed generated). So basicaly the admin disguise the fairness into two levels but we have options to check only the first level ...and no clue how to verify the second one ... aka NOT PROVABLY FAIR. My humble opinion.

I don't even understand how to verify the rolls with the given seed 
First I'd like to understand that and then I can ask how the seed is even generated 

[Bitfort]

I'm not speacialist as well but something is shady here for sure.

Have to note the standard procedure (for similar sites) is that the server seed is given (and not changing) for e.g entire one day. And published next day (and changed of course) so you can verify only bets made day before.

I have tried one thing (which if found quite interesting) in above mentioned post ....  and found the server seed is indeed changing for every bet.

This would not be totaly unfair as long as there would be any way to check fairness of this seed generation (I did not find on which basis this seed generated). So basicaly the admin disguise the fairness into two levels but we have options to check only the first level ...and no clue how to verify the second one ... aka NOT PROVABLY FAIR. My humble opinion.

I don't even understand how to verify the rolls with the given seed  
First I'd like to understand that and then I can ask how the seed is even generated  

OK, I did not realized you wanted to explain the very basics.
The thing is you are trying to understand it while using this rigged casino (which makes the entire process too complicated ). I guess the reason for this is to confuse players which seems to worked in your case ) ... I'm pretty sure if you follow verification procedure of any relevant site like primedice or freebitco you would understand.

Hope you are familiar with the hash functions: same input always results in same output ... thus you can verify if the input has not been changed (it would change the output as well).


Lets try some example (sorry for my english, hope you'll undestand it).

I'm running dice casino.
Basic rule is: Bet result is given by last two digits from sha256 hash of "provably fair string". And this string is composed as "serverSeed+ClientSeed+betID"

You will choose your own clientSeed (for this case let it be: BLEBLEBLE )

I have to provide you with (daily) serverSeed: in this case let it be: BLABLABLA
but I can't provide you this seed directly otherwise you would be able to rig the game so I will give you only it's SHA256 hash which is:
9fb037daee8774db8f25ed16f796e89e11a8825829683244ae777a5f725bddf0 (you would be able to verify this next day, after I publish the unhashed serverSeed)

Now you will make a very first bet of my casino (thus bet ID is 1)

Based on all this info i can compose the provably fair string: "BLABLABLA+BLEBLEBLE+1".
I'll hash it using sha256 which gives me: 319159c8fef7aa6cc6e49fefa4b761c47ab69be363ed7ba10906783a689dbb5f  
This gives last two digits: 95 which represents the rolled number (so if you would bet HI you would win)

To verify fairness you need to:

1 - check if I did not changed the serverSeed ( after I publish it you need to hash it and this hash has to be same as you have seen on beginning: "9fb037....25bddf0"  
2 - if everthying OK you can compose the provably fair string ("BLABLABLA+BLEBLEBLE+1") and hash it. Last two digits of this hash must correspond with the rolled number.


ufff, when I start writing this I didn't expect it will be so long.

[iluvbitcoins]

So, basically in order to verify the bet I shoul use the seed I get after placing the bet, not the one I had prior to it

And since a new seed is generated after each bet and we have no idea how it is generated, 999dice is not provably fair at all.

Does this work?
https://bitcointalk.org/index.php?topic=950605.msg10407384#msg10407384

[Joel_Jantsen]

So, basically in order to verify the bet I shoul use the seed I get after placing the bet, not the one I had prior to it

And since a new seed is generated after each bet and we have no idea how it is generated, 999dice is not provably fair at all.

Does this work?
https://bitcointalk.org/index.php?topic=950605.msg10407384#msg10407384

To be honest,their procedure looks quite complicated as compared to other provable fairness methods I have come across on different websites.What I find sketchy is this,

Keep taking groups of 3 bytes and converting to an integer, until a value less than 16 million is found. If you run out of bytes, hash it again and start over.
Find the value's modulus of 1 million

Why only 3 bytes ? Why the value would be less than 16 million ? I mean I know it's a stupid question but this doesn't look like a formula for throwing a provable fair number to me.Anyway,I'll check a real time example tomorrow or something.

[adaseb]

So, basically in order to verify the bet I shoul use the seed I get after placing the bet, not the one I had prior to it

And since a new seed is generated after each bet and we have no idea how it is generated, 999dice is not provably fair at all.

Does this work?
https://bitcointalk.org/index.php?topic=950605.msg10407384#msg10407384

The way it works is that you are only given the hashed seed, not the orignal seed before it was put thru a hash script.

Since its impossible to reverese engineer the SHA, the site can give you this seed freely. Because even if it was possible to reverse engineer the seed, you would most likely get private keys or solve Bitcoin blocks instead.

Hence with the hashed seed the casino already knows ahead of time how many bets you will win or lose.

[iluvbitcoins]

So, basically in order to verify the bet I shoul use the seed I get after placing the bet, not the one I had prior to it

And since a new seed is generated after each bet and we have no idea how it is generated, 999dice is not provably fair at all.

Does this work?
https://bitcointalk.org/index.php?topic=950605.msg10407384#msg10407384

The way it works is that you are only given the hashed seed, not the orignal seed before it was put thru a hash script.

Since its impossible to reverese engineer the SHA, the site can give you this seed freely. Because even if it was possible to reverse engineer the seed, you would most likely get private keys or solve Bitcoin blocks instead.

Hence with the hashed seed the casino already knows ahead of time how many bets you will win or lose.

Yeah, I get that, but how do I verify the fairness of bets on 999dice? 

[Bitfort]

So, basically in order to verify the bet I shoul use the seed I get after placing the bet, not the one I had prior to it

And that's the point ... because there is not fixed server seed any further discussion about bet fairness is poinless.

[veleten]

there have been multiple threads on this,999dice is NOT recommended to play at
their provably fair doesn't show until you explicitly open and click on it
this way the server knows if you are checking the rolls or not,i.e. if you don't they are free to give you any combinations of randomly created server seeds each roll
some call them scammers,some say their provably fair is not good enough
I just avoid playing there,thats all
why bother if there are better,trusted alternatives? besides 0.1% House edge sounds like they are making money on something else.... and thats something else could as well be scamming you

[adonisbtc]

no site can be 100 percent provably fair. it is better you ignore that fact and try ur luck. as long as there are players who are making profit, no issues on that.

[adaseb]

no site can be 100 percent provably fair. it is better you ignore that fact and try ur luck. as long as there are players who are making profit, no issues on that.

You have no idea what you are talking about.

Do you even know how provably fair works?

You are basically given a hash before you place your bets, and then after you are done betting you are given the unhashed seed and can verify that your bets were legimate.

Its impossible for 2 different unhashed seeds to produce the exact same hashed seed which you are given.

[iluvbitcoins]

there have been multiple threads on this,999dice is NOT recommended to play at
their provably fair doesn't show until you explicitly open and click on it
this way the server knows if you are checking the rolls or not,i.e. if you don't they are free to give you any combinations of randomly created server seeds each roll
some call them scammers,some say their provably fair is not good enough
I just avoid playing there,thats all
why bother if there are better,trusted alternatives? besides 0.1% House edge sounds like they are making money on something else.... and thats something else could as well be scamming you

That's the sole reason I'm trying to figure out their provable fairness

I've even found out about them through the scam accusation 
The button doesn't even exist anymore, you just have to click provably fair once and the hash shows itself with each bet
If it could be proven fair, even with a button, a script could be made to click it and take advantage of the low edge as soon as it IS provably fair
Which it isn't

So, nothing.