SatoshiDICE.com - The World's Most Popular Bitcoin Game

[dooglus]

I am trying to understand how does a satoshidice draw work.

As far as i have understood sd generates daily two public hashes:

HMAC hash
Position hash

You can check https://www.satoshidice.com/files/daily-secret-hash.txt all the HMAC and Position Hashes up to 31.10.2014 has been released. Why did they do this, if the hashes were only released the day after the draws?

If the draw is calculated using next formula:

Resulting String = hmac_sha512(daily_secret, "tx_id:out_index")

If someone gets tx_id:out_index they could be used to win bets unfairly as the daily_secret and positions have already been released, am i right?

They announce the *hash* of the daily secrets in advance.
They announce the daily secrets themselves at the end of each day.

That way you can check that they selected the daily secret in advance (since they published its hash) without being able to know the actual secret in advance.

[1714769603]

1714769603

[pureelite]

will this game ever be on-chain and not off-chain?

[Shogen]

will this game ever be on-chain and not off-chain?

They mentioned there will be an off chain betting in the new version of SD, but didn't mention whether they will keep the current on chain game untouched or not...

We're about to release the new version of Satoshi Dice so here's a teaser! Final testing is being made now.

Highlights

• Rapid session based off chain betting

-snip-

[dooglus]

will this game ever be on-chain and not off-chain?

It is already on-chain.

For a while they offered an off-chain version too, which they called "tribute", but from what I heard it was exploitable so they took it offline to fix it. That was approximately a year ago I guess.

[jaitor]

I am trying to understand how does a satoshidice draw work.

As far as i have understood sd generates daily two public hashes:

HMAC hash
Position hash

You can check https://www.satoshidice.com/files/daily-secret-hash.txt all the HMAC and Position Hashes up to 31.10.2014 has been released. Why did they do this, if the hashes were only released the day after the draws?

If the draw is calculated using next formula:

Resulting String = hmac_sha512(daily_secret, "tx_id:out_index")

If someone gets tx_id:out_index they could be used to win bets unfairly as the daily_secret and positions have already been released, am i right?

They announce the *hash* of the daily secrets in advance.
They announce the daily secrets themselves at the end of each day.

That way you can check that they selected the daily secret in advance (since they published its hash) without being able to know the actual secret in advance.

Can you give me an example?

I want to bet but i want to check by myself if everything is ok...

I mean if the function they are using is:

128 hex hash = hmac_sha512(daily_secret, "tx_id:out_index")

if i don't have the daily secret , and tx_id:out_index is known once the transaction is made, and that's when the 128 hex hash is calculated (the 128 HMAC hash it can't be known in advance as you don't have the tx_id:out_index, and to calculate the HMAC you need both, key and message), what's in this example your "They announce the *hash* of the daily secrets in advance"?.

[dooglus]

if i don't have the daily secret , and tx_id:out_index is known once the transaction is made, and that's when the 128 hex hash is calculated (the 128 HMAC hash it can't be known in advance as you don't have the tx_id:out_index, and to calculate the HMAC you need both, key and message), what's in this example your "They announce the *hash* of the daily secrets in advance"?.

First off, understand that "sending a transaction" is really several steps:

1) select some outputs to send
2) make a raw transaction
3) sign it with your private keys
4) broadcast it to the network

Note that steps 1 through 3 can happen entirely offline, and by the end of step 3 your transaction ID is known.

If you knew the daily secret, you could combine it with your transaction's ID, calculate the HMAC, and see if you would win or not. Then you could decide whether to run step 4 and broadcast the transaction, or go back to step 3, sign it again (which has a random element, and will change the transaction ID) and repeat until you get a transaction ID that you like (because it wins).

So you can't know the daily secret before you bet, or you could cheat as I just described.

The site tells you the daily secret once it has finished using it. Usually around 24 hours after it has finished using it.

All they tell you before you bet is the HASH of the daily secret. They use a one-way hash: it's very easy to get from the secret to its hash, and almost impossible to go the other way.

So you can make a note of the hash they have given you, then a couple of days later once they have published the secret itself you can hash it and check that you get the hash they gave you before you bet. That way you can be sure that they didn't cheat and pick a secret just to make you lose.

Is that clearer?

[jaitor]

if i don't have the daily secret , and tx_id:out_index is known once the transaction is made, and that's when the 128 hex hash is calculated (the 128 HMAC hash it can't be known in advance as you don't have the tx_id:out_index, and to calculate the HMAC you need both, key and message), what's in this example your "They announce the *hash* of the daily secrets in advance"?.

First off, understand that "sending a transaction" is really several steps:

1) select some outputs to send
2) make a raw transaction
3) sign it with your private keys
4) broadcast it to the network

Note that steps 1 through 3 can happen entirely offline, and by the end of step 3 your transaction ID is known.

If you knew the daily secret, you could combine it with your transaction's ID, calculate the HMAC, and see if you would win or not. Then you could decide whether to run step 4 and broadcast the transaction, or go back to step 3, sign it again (which has a random element, and will change the transaction ID) and repeat until you get a transaction ID that you like (because it wins).

So you can't know the daily secret before you bet, or you could cheat as I just described.

The site tells you the daily secret once it has finished using it. Usually around 24 hours after it has finished using it.

All they tell you before you bet is the HASH of the daily secret. They use a one-way hash: it's very easy to get from the secret to its hash, and almost impossible to go the other way.

So you can make a note of the hash they have given you, then a couple of days later once they have published the secret itself you can hash it and check that you get the hash they gave you before you bet. That way you can be sure that they didn't cheat and pick a secret just to make you lose.

Is that clearer?

understood perfectly. Thanks!

[SatoshiDICE_PR]

First off, understand that "sending a transaction" is really several steps:

1) select some outputs to send
2) make a raw transaction
3) sign it with your private keys
4) broadcast it to the network

Note that steps 1 through 3 can happen entirely offline, and by the end of step 3 your transaction ID is known.

If you knew the daily secret, you could combine it with your transaction's ID, calculate the HMAC, and see if you would win or not. Then you could decide whether to run step 4 and broadcast the transaction, or go back to step 3, sign it again (which has a random element, and will change the transaction ID) and repeat until you get a transaction ID that you like (because it wins).

So you can't know the daily secret before you bet, or you could cheat as I just described.

The site tells you the daily secret once it has finished using it. Usually around 24 hours after it has finished using it.

All they tell you before you bet is the HASH of the daily secret. They use a one-way hash: it's very easy to get from the secret to its hash, and almost impossible to go the other way.

So you can make a note of the hash they have given you, then a couple of days later once they have published the secret itself you can hash it and check that you get the hash they gave you before you bet. That way you can be sure that they didn't cheat and pick a secret just to make you lose.

Good description, Dooglus. We are making the process clearer and also something similar in the FAQ. Most importantly though, is the new upcoming game that proves the fairness in a much easier way!

[SatoshiDICE_PR]

will this game ever be on-chain and not off-chain?

No, we're releasing the new off chain game within 1-2 weeks.

[SatoshiDICE_PR]

@gas7uazz - Well, as they stated in the previous post, I think the max bets will rise again with the new tribute version

Also, wow, nice stats you have there. I think I have a wager of max. 100 btc in my whole btc gambling history. Keep it up!

Yes, highrollers will be able to play again. Final testing and some optimisations are going on now before the release.

[RocketSingh]

will this game ever be on-chain and not off-chain?

It is already on-chain.

For a while they offered an off-chain version too, which they called "tribute", but from what I heard it was exploitable so they took it offline to fix it. That was approximately a year ago I guess.

What does it mean by on-chain and off-chain betting ?

[dooglus]

What does it mean by on-chain and off-chain betting ?

On-chain betting:

  Each bet you place is in the form of a Bitcoin transaction. Each bet you win sends you your winnings in a new transaction.

Off-chain betting:

  You deposit some coins into an account on a website. You get to make lots of bets on the site without making any more Bitcoin transactions. You have a "balance" on the site which is really just an entry in a database. Then you withdraw your winnings to your wallet.

Pros and cons:

On-chain betting has a public audit trail. You can prove you made each bet.
On-chain betting uses a lot of space on the blockchain. Everyone node has to store every bet forever (or until we invent pruning).
On-chain betting is typically slow, since we need to wait for confirmations to prevent double-spends.

[SatoshiDICE_PR]

What does it mean by on-chain and off-chain betting ?

On-chain betting:

  Each bet you place is in the form of a Bitcoin transaction. Each bet you win sends you your winnings in a new transaction.

Off-chain betting:

  You deposit some coins into an account on a website. You get to make lots of bets on the site without making any more Bitcoin transactions. You have a "balance" on the site which is really just an entry in a database. Then you withdraw your winnings to your wallet.

Pros and cons:

On-chain betting has a public audit trail. You can prove you made each bet.
On-chain betting uses a lot of space on the blockchain. Everyone node has to store every bet forever (or until we invent pruning).
On-chain betting is typically slow, since we need to wait for confirmations to prevent double-spends.

Well put, we'll put this in the FAQ section!

[dooglus]

What does it mean by on-chain and off-chain betting ?

On-chain betting:

  Each bet you place is in the form of a Bitcoin transaction. Each bet you win sends you your winnings in a new transaction.

Off-chain betting:

  You deposit some coins into an account on a website. You get to make lots of bets on the site without making any more Bitcoin transactions. You have a "balance" on the site which is really just an entry in a database. Then you withdraw your winnings to your wallet.

Pros and cons:

On-chain betting has a public audit trail. You can prove you made each bet.
On-chain betting uses a lot of space on the blockchain. Everyone node has to store every bet forever (or until we invent pruning).
On-chain betting is typically slow, since we need to wait for confirmations to prevent double-spends.

Well put, we'll put this in the FAQ section!

Dear Sir/Madam,

Do you have any vacancies?

I would like to apply for the position of "stupid question answerer" for satoshidice.

lol

[ingrownpocket]

What does it mean by on-chain and off-chain betting ?

On-chain betting:

  Each bet you place is in the form of a Bitcoin transaction. Each bet you win sends you your winnings in a new transaction.

Off-chain betting:

  You deposit some coins into an account on a website. You get to make lots of bets on the site without making any more Bitcoin transactions. You have a "balance" on the site which is really just an entry in a database. Then you withdraw your winnings to your wallet.

Pros and cons:

On-chain betting has a public audit trail. You can prove you made each bet.
On-chain betting uses a lot of space on the blockchain. Everyone node has to store every bet forever (or until we invent pruning).
On-chain betting is typically slow, since we need to wait for confirmations to prevent double-spends.

Well put, we'll put this in the FAQ section!

Dear Sir/Madam,

Do you have any vacancies?

I would like to apply for the position of "stupid question answerer" for satoshidice.

lol

That really ins't a stupid question, but there's definitely many that are and need answering.

[dooglus]

Dear Sir/Madam,

Do you have any vacancies?

I would like to apply for the position of "stupid question answerer" for satoshidice.

lol

That really ins't a stupid question, but there's definitely many that are and need answering.

Thanks!

When do I start?

[SatoshiDICE_PR]

What happened to satoshidice? Why do no people bet there anymore?

1. they do, just not very much

2. the house edge is almost twice that of any other dice site (1.9% vs 1%)

3. the maximum bet sizes have dropped off significantly

4. the range of bets available has been cut

5. the site hasn't kept up with innovations in dicing:

5a. betting is on-chain and slow
5b. bet verification involves waiting until the end of the day for the secret to be revealed
5c. other sites allow you to specify your own odds; sd still has a very limited list of odds
5d. other sites allow you to bet 'high' or 'low'. sd still only lets you bet 'low'
5e. there's no on-site chat, so there's less of a feeling of community around the site

It's hard to say which of these are most significant, but they probably all play a part. It seems like the site was just left to die, even before it was sold for a huge number of BTC.

1. This will is expected to increase a lot soon for the reason explained below.

3. Maximum bet sices will increase a lot. We will gradually increase to up to at least 100 as biggest win.

4. With bigger hot wallet, the bets with higher payout will become available again.

5. We will also offer a fast off chain game with big bankroll where you can choose any bet you would like. You will be able to create several bets per second, compete on leader boards, see your daily luck, play with nice sound and particle effects and more.

[dooglus]

What happened to satoshidice? Why do no people bet there anymore?

1. they do, just not very much

2. the house edge is almost twice that of any other dice site (1.9% vs 1%)

3. the maximum bet sizes have dropped off significantly

4. the range of bets available has been cut

5. the site hasn't kept up with innovations in dicing:

5a. betting is on-chain and slow
5b. bet verification involves waiting until the end of the day for the secret to be revealed
5c. other sites allow you to specify your own odds; sd still has a very limited list of odds
5d. other sites allow you to bet 'high' or 'low'. sd still only lets you bet 'low'
5e. there's no on-site chat, so there's less of a feeling of community around the site

It's hard to say which of these are most significant, but they probably all play a part. It seems like the site was just left to die, even before it was sold for a huge number of BTC.

1. This will is expected to increase a lot soon for the reason explained below.

3. Maximum bet sices will increase a lot. We will gradually increase to up to at least 100 as biggest win.

4. With bigger hot wallet, the bets with higher payout will become available again.

5. We will also offer a fast off chain game with big bankroll where you can choose any bet you would like. You will be able to create several bets per second, compete on leader boards, see your daily luck, play with nice sound and particle effects and more.

Thanks for the answer.

You missed addressing point 2. Will you continue to offer almost double the house edge of everyone else?

Dice sites have standardised on a 1% house edge; I can't think of a single site other than satoshidice that charges more than that.

[SatoshiDICE_PR]

What happened to satoshidice? Why do no people bet there anymore?

1. they do, just not very much

2. the house edge is almost twice that of any other dice site (1.9% vs 1%)

3. the maximum bet sizes have dropped off significantly

4. the range of bets available has been cut

5. the site hasn't kept up with innovations in dicing:

5a. betting is on-chain and slow
5b. bet verification involves waiting until the end of the day for the secret to be revealed
5c. other sites allow you to specify your own odds; sd still has a very limited list of odds
5d. other sites allow you to bet 'high' or 'low'. sd still only lets you bet 'low'
5e. there's no on-site chat, so there's less of a feeling of community around the site

It's hard to say which of these are most significant, but they probably all play a part. It seems like the site was just left to die, even before it was sold for a huge number of BTC.

1. This will is expected to increase a lot soon for the reason explained below.

3. Maximum bet sices will increase a lot. We will gradually increase to up to at least 100 as biggest win.

4. With bigger hot wallet, the bets with higher payout will become available again.

5. We will also offer a fast off chain game with big bankroll where you can choose any bet you would like. You will be able to create several bets per second, compete on leader boards, see your daily luck, play with nice sound and particle effects and more.

Thanks for the answer.

You missed addressing point 2. Will you continue to offer almost double the house edge of everyone else?

Dice sites have standardised on a 1% house edge; I can't think of a single site other than satoshidice that charges more than that.

We'll give back part of it in leader board prizes and later on in the tribute system where players will even be able to earn coins.

[BayAreaCoins]

Dice sites have standardised on a 1% house edge; I can't think of a single site other than satoshidice that charges more than that.

Dice.Ninja