[How-To] Make a provably fair giveaway ✅

[seoincorporation]

The hard way:

The biggest hex number between 0000 and FFFF win.

Client Seed(Hidden for public): 5d509c8bfcb6834e6d240b53a41b52c311daa127a9acc7b909ba37dcf3360d00
Giveaway Seed (client seed Sha256): c9a8bfd5a60af5533b0da6ada2e5202318d92fddc4b2f948625467cbff4709b4

Sha256 tools: https://xorbin.com/tools/sha256-hash-calculator

Now lets say 3 users join to the giveaway.

USERS - Post Date
UserA October 12, 2022, 05:39:50 PM
UserB October 12, 2022, 05:39:40 PM
UserC October 12, 2022, 05:39:30 PM

We can take that users data to make a string with the client seed, then take the last 4 digits from the sha result and se who is the winner.

Code:

5d509c8bfcb6834e6d240b53a41b52c311daa127a9acc7b909ba37dcf3360d00:UserA October 12, 2022, 05:39:50 PM

SHA256:

Code:

cb076f9ecbf7561c4714e44ea581266be975018278789653b7159dc2fddf9d40

Last 4 digits:

Code:

9d40

This way we have:

UserA 9d40
UserB b619
UserC dd39

If you aren't good with hex, then you can conver that result to decimal to verify who has the biggest number:
https://www.rapidtables.com/convert/number/hex-to-decimal.html

9d40→40256, b619→46617, dd39→56633

That way we have a fair winner (UserC), then we only have to make public the client seed to let the people verify the result and send the prize.

The easy way:


Choose a number between 1 and 1000.

Game result phrase:

Code:

The winning number of the "My Business" Givaway started on date 02/05/2022:10:40 is the number 472

Sha256:

Code:

aa529508f4f5b51ecc7948b26dd917883cd0b86c34356ee516ba156315f8dd39

If you only make public the sha256, that way users know the game will be not rigged.

Outro.

I create this guide because i have seen a lot of giveaways in the past selecting the users from random.org or wheelofnames.com, and that isn't a fair way to select a winner because the organizer could roll multiple times the site until he gets the result he wants. So, i highly recommend to always provide a seed or a hash to make the game fair for all.  

Update.

As some users realize both ways could be rigged with collusion. And the way to make it 100% provably fair is to bring an element from the future, like the hash of the block number 100 from now and add that data to the string before the sha256 encryption.

[seoincorporation]

I am not expert at something like this but is this for gamblers wbo wanted to check the casino if they really are provably fair when it comes to their giveaways or to determine if the game results is not rigged by using this steps you shared?. I am quite confused if purpose is what I just explained earlier or you share this because you are doing yourself a giveaway which this will be used to determine in your giveaway if I am not wrong.

Hello nakamura12, this is just a tutorial for those users who want to make a giveaway in the forum on a fair way for the users.

The casinos use a similar logic to prove their fairness and is important to teach people how to use this tools and the logic behind it, i'm not planing to make a giveaway, i just want to show you the right way to do it.

[notblox1]

I create this guide because i have seen a lot of giveaways in the past selecting the users from random.org or wheelofnames.com, and that isn't a fair way to select a winner because the organizer could roll multiple times the site until he gets the result he wants. So, i highly recommend to always provide a seed or a hash to make the game fair for all.  

My least favorite phrase is provably fair, because it was abused many times in this forum...but I will say this is well written guide,
and it's very clear to everyone what is happening and how the winners are selected.
Let me tell you one secret that is not really a secret  people are mostly using random.org or wheelofnames because it's easier for them, and they want to save time.
Nobody knows how winners are selected on those websites and you can't prove what happened in the background.

[PX-Z]

Thanks for this. I'll bookmarked this for now i might use this to my future project for giveaways. Because i just use randomize function in php for random results but it lacks for transparency.
Well, i'm just new learning programming btw.

[worle1bm]

These types of guides are really helpful although I don't understand technical part but have seen the client seed and hash things in giveaways that casino also uses to make it probably fair and users can verify them and this is the case with bets also but you have provided with two ways a giveaway can be fair but I think the hard one is the right way to go and choose the winner as in most cases.

[NeuroticFish]

Choose a number between 1 and 1000.
[~snip~]
If you only make public the sha256, that way users know the game will be not rigged.

Imho this is an imperfect solution since a "host" with bad intention can also tell "a friend" (or his alt) what is the number he chose for the winner.
I think that a method/algorithm where the host also doesn't know from start what will be the winning number is much better.

[LUCKMCFLY]

A very interesting thread colleague, as always, the truth is that in some sites they do not apply that way of making draws demonstrably fair, whenever I have been in draws they use the google algorithm, which curiously is not very accepted or reliable for casinos, no I remember the name well, I know that it has an associated random, that at the programming level I don't know if it is or if it has a way to exploit it, however it is wonderful how you present it, I am sure that casino platforms in general you will pay attention to this, on twitch mainly it would have been good if some streamers had used it.

[savetheFORUM]

I create this guide because i have seen a lot of giveaways in the past selecting the users from random.org or wheelofnames.com, and that isn't a fair way to select a winner because the organizer could roll multiple times the site until he gets the result he wants. So, i highly recommend to always provide a seed or a hash to make the game fair for all.  

My least favorite phrase is provably fair, because it was abused many times in this forum...but I will say this is well written guide,
and it's very clear to everyone what is happening and how the winners are selected.
Let me tell you one secret that is not really a secret  people are mostly using random.org or wheelofnames because it's easier for them, and they want to save time.
Nobody knows how winners are selected on those websites and you can't prove what happened in the background.

Abused in what way? But my guess is that a crypto casino will lie and say that their games are provably fair but they are actually not. Is that what you mean? We can just say that those casinos are not trusted but we shouldn't put a hate to the word provably fair itself. Provably fair is important in the world of cryptos because it was like its main security or indication to tell if the service is legit or not but no doubt the op's post is great.

It will help those giveaway organizers to use it instead of the online tools that they are commonly using. It's kind a weird though if they are dealing with cryptos and then they won't use something which are also related to it.

[seoincorporation]

...
Imho this is an imperfect solution since a "host" with bad intention can also tell "a friend" (or his alt) what is the number he chose for the winner.
I think that a method/algorithm where the host also doesn't know from start what will be the winning number is much better.

You have a good point here and this is why some people use future block hash as part of the equation. And this way even if the organizer tell de secret seed to a friend it will be impossible to cheat.

I didn't add that to my steps because i want to make it simple and teach how the encryption helps to make things provably fair or the most simple way. 

[Little Mouse]

...
Imho this is an imperfect solution since a "host" with bad intention can also tell "a friend" (or his alt) what is the number he chose for the winner.
I think that a method/algorithm where the host also doesn't know from start what will be the winning number is much better.

You have a good point here and this is why some people use future block hash as part of the equation. And this way even if the organizer tell de secret seed to a friend it will be impossible to cheat.

I didn't add that to my steps because i want to make it simple and teach how the encryption helps to make things provably fair or the most simple way. 

I'm not an expert on these things, to be honest, I had never thought of learning this but it seems I have to learn it very soon. Not every time LoyceV is going to get it done freely. I think this method by LoyceV is a fairly enough fair giveaway method when it comes to picking the winner without having any influence. I used to use a centralized system though it was paid where I didn't have influence and every roll would have a link to verify. But still, this seems the best to me.

[fathafraink]

The hard way:

The biggest hex number between 0000 and FFFF win.

Client Seed(Hidden for public): 5d509c8bfcb6834e6d240b53a41b52c311daa127a9acc7b909ba37dcf3360d00
Giveaway Seed (client seed Sha256): c9a8bfd5a60af5533b0da6ada2e5202318d92fddc4b2f948625467cbff4709b4

Sha256 tools: https://xorbin.com/tools/sha256-hash-calculator

Now lets say 3 users join to the giveaway.

USERS - Post Date
UserA October 12, 2022, 05:39:50 PM
UserB October 12, 2022, 05:39:40 PM
UserC October 12, 2022, 05:39:30 PM

We can take that users data to make a string with the client seed, then take the last 4 digits from the sha result and se who is the winner.

Code:

5d509c8bfcb6834e6d240b53a41b52c311daa127a9acc7b909ba37dcf3360d00:UserA October 12, 2022, 05:39:50 PM

SHA256:

Code:

cb076f9ecbf7561c4714e44ea581266be975018278789653b7159dc2fddf9d40

Last 4 digits:

Code:

9d40

This way we have:

UserA 9d40
UserB b619
UserC dd39

If you aren't good with hex, then you can conver that result to decimal to verify who has the biggest number:
https://www.rapidtables.com/convert/number/hex-to-decimal.html

9d40→40256, b619→46617, dd39→56633

That way we have a fair winner (UserC), then we only have to make public the client seed to let the people verify the result and send the prize.

The easy way:


Choose a number between 1 and 1000.

Game result phrase:

Code:

The winning number of the "My Business" Givaway started on date 02/05/2022:10:40 is the number 472

Sha256:

Code:

aa529508f4f5b51ecc7948b26dd917883cd0b86c34356ee516ba156315f8dd39

If you only make public the sha256, that way users know the game will be not rigged.

Outro.

I create this guide because i have seen a lot of giveaways in the past selecting the users from random.org or wheelofnames.com, and that isn't a fair way to select a winner because the organizer could roll multiple times the site until he gets the result he wants. So, i highly recommend to always provide a seed or a hash to make the game fair for all.  

The true meaning of sharing and caring. It is very good to provide a method or even a workaround for this. I'll try to share this with anyone who needs it, I'm sure it's really needed.

[Fivestar4everMVP]

Thank you OP for this tutorial, its a valuable one which I believe will be of great help to many of us in the future, you have passed to me an idea of how to organize a giveaway that can be truly fair.

The tutorial seems to me like one where the hard is the easy and the easy one the hard, I am just trying to say that I find the first tutorial more easier to understand and follow than the second 😂😂.

Bookmarked.

[LoyceV]

Choose a number between 1 and 1000.
[~snip~]
If you only make public the sha256, that way users know the game will be not rigged.

Imho this is an imperfect solution since a "host" with bad intention can also tell "a friend" (or his alt) what is the number he chose for the winner.

I think both (hard and easy) can be rigged. You explained the second one already. The first one can be rigged too: by sharing the client seed with a friend, it's possible for them to calculate the best time to post to get a winning result. Posting at exactly the right time is easy, so they're almost certain they'll win.
It's also easy to fix, by adding a future block hash to the equation.

[NeuroticFish]

I think both (hard and easy) can be rigged. You explained the second one already. The first one can be rigged too: by sharing the client seed with a friend, it's possible for them to calculate the best time to post to get a winning result. Posting at exactly the right time is easy, so they're almost certain they'll win.
It's also easy to fix, by adding a future block hash to the equation.

Woah. You're right! And I should have been thinking on that too.
And indeed, we should stick to what we know it's fair: the hash of a future block.
It's used in the collectible raffles for so long, people should already know how that works.

[Hispo]

Thanks for this guide. Coincidentally this same week I was wondering how to draw a winner in a provably fair way.
I honestly expected the process to be longer and more difficult, but it looks like something which only would take some minutes to do.

I also like how you provided both examples: one where each user do not choose their input for the hash function and other one when they choose numbers  

Could you make a short tutorial to code the process on python?
I have not messed with cryptographic functions on python yet, but I would like to.

[yahoo62278]

I create this guide because i have seen a lot of giveaways in the past selecting the users from random.org or wheelofnames.com, and that isn't a fair way to select a winner because the organizer could roll multiple times the site until he gets the result he wants.

I've seen lot's of streamers run giveaways doing the wheelofnames.com site. I think if it's done live then it is pretty fair. I know you're giving a tutorial of non live giveaways, but I thought it was worth mentioning that wheelofnames isn't automatically a scam.