Topic: Satoshi Dice -- Statistical Analysis - page 62. (Read 192889 times)

I think you're confusing two hashes.  There's:

* The hash of the day's secret number.  It was published months ago and won't change.
* The hash of your bet transaction, also known as the transaction ID.  It is created (by your client, not by SatoshiDice) when you make a payment.  It doesn't change.


You get to pick your transaction ID if you want to, as follows:

1. back up your wallet.dat file
2. turn off your Internet connection
3. tell your wallet to send a bet to SD
4. check the transaction ID
5. if you don't like it, quit the wallet program, restore your wallet.dat from the backup, restart the wallet program, and go back to step 3, but add 1 satoshi to the bet amount.  that will cause a completely different transaction ID to be used
6. turn your Internet connection back on
7. wait for the wallet to send the transaction (only the most recent one, whose txid you liked) out to the network

There's no point doing any of this if you don't know the daily secret, because you can't tell with txid values to "like" - you would want to like just the ones that are going to win, but you can't tell that without the secret, which you won't know until tomorrow.  You usually just create a transaction and instantly broadcast it, but using the steps above it's possible to check the txid before broadcasting it, and delete (by restoring a backup) the transaction so nobody but you ever knows you made it.

Your transaction ID is computed from all of your transaction data, including:
* Inputs (the source of the coins you're spending)
* Destination addresses and amounts
* Your signature (apparently containing some randomness chosen by you)

All of these (except the destination address obv.) are provided by you or by your bitcoin client on your behalf when you create a transaction. So when you click "send" in your wallet, your client fills in the transaction details you didn't explicitly specify and the result determines the transaction ID.

You can play with transaction IDs using, for example, the brainwallet.org Transactions page. There you can see your transaction ID even before you send the transaction and you can avoid sending it if you don't like the ID.

Transaction ID is also called transaction hash (because it is hash of all of the transaction data), and is displayed under "hash" field in brainwallet.org UI.

Ok im so conufsed with this then. How can i chose my transaction ID? All i do is open my wallet and copy and paste the address in which i want to send the corresponding bet to. Where is it that im chosing the ID? CAn you explain step by step what happens right before i place my bet so I can understand it more?

ryan, the lucky number is calculated in a deterministic (non-random) way from two things:
* satoshidice secret (chosen in advance and fixed; becomes known later)
* your transaction id (chosen by you)

There is nothing satoshidice can do to change the outcome. If anything, it is you who could be cheating by choosing good transaction ids (if you knew their secret).

I understand but it assigns a "lucky" number to my bet. All of this "ahead of time" nonsense doesnt mean anything. It isnt picking my number before i bet. The lucky number however it comes about is assigned once i place my bet not before i  place it..

No the hash is a HASH of the secret number.  A hash isn't random.  The SECRET NUMBER is random and then the hash is computed and provided ahead of time. It is proof of the secret number without revealing the secret number.  When the secret number is revealed you can hash it yourself and verify it hasn't been changed.

THE HASH OF THE SECRET NUMBER IS PROVIDED BEFORE YOU PLACE A BEST.  BEFORE ANYONE ON THE PLANET EVER PLACED ANY BETS.

What im saying is it doesnt matter what the secret number is since it has to correspond with the hash. The hash is after you place the bet. Obviously. Where does this hash come from? A random draw?

It's possible to make a few small bets if outcome for a gambler is too good. No... Seems it's impossible.

EDIT: Anyway they get their 1.9%, so there is no reason to cheat.

The hashes for the secret number of each day for the next (1000?) days has been published in advance.   Thus you can verify after the fact verify the secret number for your day is indeed the one which produces the hash for that day and thus the secret number wasn't changed to "screw you".  

You're not getting it.

They picked all the daily secrets before starting operations, and published all the hashes then too.

So the day after you bet, they reveal the secret they used, and you can verify that its hash matches the hash they published months ago.  That means they used the secret they made up months ago (or they've cracked the hash, in which case there's much bigger money to be made elsewhere).

In addition to that, they use the same secret for everyone - they only use one secret per day.  So even if they did have some way of switching secrets 'at the last minute', they'd have to find one that screwed you, but which also didn't change the result of any of the bets they'd already processed that day.

If I was you I would read up on how it works and see if you can think of any way they could be cheating.  It's easy to say "they can pick any number they want" when you don't understand how things work.  But if you can make such a statement once you understand the mechanics of it, that would be interesting.

But that proves nothing. They can pick any number they want with any hash they want. You place your bet they use some hash that will screw you.

Click the 'verification' link in the top right corner of their site to read about how they pick the number.

In short it goes like this:

* at the dawn of time, they picked a random 'secret' number for each day, and published the hash of each secret number
* when they receive your bet transaction, they use that day's secret and your bet's transaction ID to make your magic number.  this is done using a well known, published algorithm.  you could do it yourself if you knew their secret
* at the end of the day, they publish that day's secret, and start using the next day's secret

So a day after you place your bet, they publish the secret they used.  You can check that the hash of the secret matches the hash they showed you in advance (so you can be sure they didn't make up a special secret just to make your bet lose) and you can also run the algorithm that combines the secret with your transaction id and check that the magic number they gave you is right.

This game robs me steady lol. ITs alwasy throwing out 61000 or whatever when i do large bets with under 60000. I dont care what anyone says its rigged. Show me that its not rigged when I place my bet. IT sees my bet and address. How does it come up with the number when I push send money? IT doesnt come up wit hthe number before I  bet obviously.

Been a rough last few days for the house.