Quoting the OP as requested.
Hi,
I've decided to host and organize a simple raffle. But it is not free. So therefore I am posting this in the Gambling section.
Dabs Raffle Number 1
a raffle style lottery using bitcoins
transparent
play instantly - no registration required
cheat-proof
95% payout of funds
provably fair
cryptographically verifiable
no blockchain spam
How to Play:
Send any multiple of 0.01 to:
1K7TmkJ5MT95nGbVgDxp1Vi8LT6ZBEYEcF
using compatible bitcoin wallet software, where you can prove ownership of the sending address.
See list below.
1K7TmkJ5MT95nGbVgDxp1Vi8LT6ZBEYEcF
I am Dabs on bitcointalk.org and this is my personal raffle, lottery or game.
IGmnBYcfwDVb83ZzJPJ59DzZaF8B4hhrac9P/vCiOhIktxftu1sgaoX6U/0/POhfOufBtI+4vesoFbjA1EY9P7s=
You can opt to do one of two things after sending the bitcoins:
1. That's it. You are effectively anonymous. If you win, you get your winnings sent to the address you sent your bet from. If you sent from more than one address, the winnings will be sent to one of them.
2. Post here your transaction ID, your sending address, and sign it (using the message signing feature of bitcoin.)
If 1. Then just wait to see if you win.
If 2. If you win, you can post here if you want your winnings sent to another bitcoin address. You must prove ownership by signing both messages.
All payments received prior to deadline is part of the raffle.
Deadline is May 20, 2013 or the first block after that time.
If it is not listed here assume it is not compatible.
Note: Any method that sends BTC using only your own private keys is compatible.
Bitcoin
Electrum
Armory
BitcoinJ
MultiBit
Blockchain.info
Blockchain (Android)
BitcoinSpinner (Android)
Bitcoin Wallet (Android)
Blockchain (iOS)
Will NOT work: Any Shared Wallets such as BitPay, Mt.Gox, localbitcoins.
If you are unsure, sending some BTC to Blockchain.info, then buying the tickets with it, is quick and easy.
About Dabs' Raffle:
This is a raffle style lottery. Therefore, the odds of winning scale with the jackpot size compared to ticket price. No matter how small or big the jackpot, the price of each ticket, is a good deal. 95% of tickets sales go to the winner.
By using bitcoins for a lottery a couple unique features are now possible:
- the players identities are unknown but all the tickets are known
- every ticket purchased can be viewed by everyone along with the senders bitcoin address
- each ticket is permanent and can't be altered because it is stored inside the blockchain
- the pot size can not be faked as anyone can check the lottery address and verify it
The players can be known too. Just post here.
Most importantly, it's impossible to manipulate who wins or fake a payment to the wrong person because:
- each ticket has a unique number that is permanent (transaction hash)
- using some block data and hashing with SHA-256
- the transaction hashes stored in the blockchain are then used to calculate the winner in an impossible to predict way
- a secret known only by me is hashed and published so I can not change the secret later
- the secret is then published after the deadline
- the winnings are then sent to the EXACT same address that bought the ticket or to an address that you choose.
All of this can be monitored and verified by anyone and is recorded in the blockchain.
Good Luck.
After the draw all tickets and their hashes will be posted along with the winner.
How I will compute your hashes:1. Get your transaction id, appending a 10 digit number depending on how much you sent.
2. use my secret
3. hash them together as one string
4. sort the hashes
The secret is secret until I publish it, but the SHA-256 hash of that string is:
dcc369beedaba36b1f1b794b75228c16daa2adb9d8fb60b5cd2a3f68ea96a2daIf you send exactly 0.01 then I will take your transaction ID and append a 10 digit number as 0000000000 with leading zeros.
If you send more than 0.01 then I will take your transaction ID and append a 10 digit number for every multiple of 0.01 with leading zeros, starting at 0000000001.
Every fraction of bitcoins less than 0.01 will not be counted, so if you send 0.0199 I will consider that as still 1 bet. The rest, I will consider as a donation. Thank you.
Examples:If you send 0.01, then your transaction id is used like this:
sha256("txid0000000000secret")
If you send 0.05, then your transaction id is used like this:
sha256("txid0000000000secret")
sha256("txid0000000001secret")
sha256("txid0000000002secret")
sha256("txid0000000003secret")
sha256("txid0000000004secret")
Where:
txid = transaction id in hex as it appears in bitcoin-qt or blockchain
0000000000 = your first ticket or only ticket
0000000001 = your next ticket.
secret = my secret, no one else knows until after
Ten (10) digits is used just in case someone sends me a large number of coins.
The winner is the hash with the lowest value.
I will then send 95% of the total pot to the winner.
Some Questions:Why am I keeping 5%?1. This is my game. If you don't like the rules, don't play.
2. I am going to do all the hashing manually. If I get more than a few hundred bets, I will have to figure out a way to do this with software.
3. If 100 people play and send 0.01, the winner gets 0.95 and I keep 0.05, I think that is fair enough for my efforts.
4. If 1000 people play and send 0.01, the winner gets 9.5 and I keep 0.5, I think that is fair enough considering I might be doing this manually.
5. If 10,000 people play, I'm going to have to code something or someone else can donate the source for this.
Although I said you can send from multiple addresses, as that's how bitcoin works, I would prefer you send your bet from a single address.
Will you use escrow?I could. Do you have someone in mind? His fees will have to be deducted from the total. I don't want to bug any of them and I'm trying to be my own escrow, but I understand if there is any hesitation.
For reference, I am doing a group buy for ASIC chips and the address used there is holding at least 30 BTC (could be more by now.) I won't update this post to reflect the current amount, you can go check there for yourself.
Will you make a website for this?Not any time soon. There is no need for a website really. Anyone and everyone can verify the winning ticket.
How long is the secret?It is alphanumeric 64 characters long. The SHA-256 hash of that string is:
dcc369beedaba36b1f1b794b75228c16daa2adb9d8fb60b5cd2a3f68ea96a2da
I will publish the secret after the deadline is over. Then actually, anyone else can compute who is the winner.
You can compute that the secret and the hash is the same, the length prevents anyone else from attempting to cheat, including myself.
What if you change the secret or the rules?Someone else quote me. Then I can't change the secret, the hash, or the rules. The most I could do is cancel the game and refund everyone their bets.
Why is the deadline May 20?Because I don't want it too long so I thought about a week from now is just right. Maybe the next one, depending on how this turns out.
Is the deadline really May 20?Well, if you manage to put a bet in 5 minutes after midnight, I might consider it. I am doing this manually. I will just post here that the game is over or the deadline has been met, and anything sent in after that is not included in the game. And I am probably in a different time zone from you, so yeah, give or take 24 hours. It's over when I say it's over.
What if two tickets get the exact same hash result? (a collision)In the rare case that happens, I will split the winnings among the two winners.
What if three?I'll divide it as well. Extremely rare, but it might happen.
Is this a scam?Don't bug me. Don't play. I am doing this as an experiment, and like I said I already am publicly holding at least 30 BTC of other people's money (eventually, that will reach more than 800 BTC if it ever completes.)
Will there be a game number two?Maybe. I don't know. Depends on how much work it is to run this, or if I can figure out a way to automate it (I'm sure it can be, but my brain isn't working now.)
Ok, so.... the game starts ... now.
Dabs
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