Bitcoin Forum

Moved!

Not very much familiar with cryptography, as I'm just starting to get my grasp of it, but I think that it is not randomly generated and some algorithms are required to produce such a hash. See this page (https://en.bitcoin.it/wiki/How_bitcoin_works) for more info. If hashes are randomly calculated in bitcoin, then algorithms would be pretty much useless in this case.

Thank brother & i'm waiting for a clear answer , i wonder if we really are able to calculate all the hash or just the first part of its ?

A transaction hash is a hash of the transaction. A "hash" is a computation that is done on data and results in a value that has useful properties, including relative uniqueness, the appearance of randomness, and an inability to recreate the original data. A transaction hash is also known as a transaction ID, or txid.

In Bitcoin, transaction hash = SHA256(SHA256(transaction))

So ? can it be calculated OR NOT  :)  Like if you give me your btc address and i wanted to send you 5$ But i want to know AND CALCULATE the tx hash before sending the payment to you is it possible ?

Hashes of the same data are always the same. However, the data inside a transaction is not always the same. A transaction includes a signature, which includes random numbers thus the data is not always known so the hash cannot be calculated without actually creating and signing a transaction.

Just found this one out, turns out you can calculate a transaction hash as explained by the former lead dev Gavin Andresen, though I don't know whether it is applicable on your query. Link --> https://bitcointalk.org/index.php?topic=54451.msg649253#msg649253

That depends on what information you have.

If you have the exact transaction, then you will always be able to calculate the hash.  If you do not have enough information to build the exact transaction, then you will not be able to calculate the hash.


Yes.  First you would build the transaction.  Then you could hash it and find out what its hash will be.  Then, if you want to, you can send the transaction.

If I ask you to do a simple addition problem for me, can you tell me the answer before I tell you the problem?

No?

Ok, then if I tell you the two numbers that I want you to add together can you tell me what their sum is?

Yes?

A hash is simply a math problem.  It's a bit more complex than basic addition, but if you know the inputs you can calculate the outputs.  If you don't know the inputs it is impossible to calculate the outputs.

So its possible to know the transaction hash (if i'm sending) but its impossible to know the tx hash if i'm recieving the payment :p ok thank you guys awesome!


Edit: is there anything that i cant know the results of it only after i send the payment ?

If you are sending the bitcoins, then you are creating the transaction, so you can know the hash after you create the transaction, but before it is published. But if you are the only one that knows the details of the transaction, then you are the only one that can know the transaction hash before the transaction is published.

Edit: is there anything that i cant know the results of it only after i send the Bitcoin payment ?

No once you create and sign the transaction, you know everything about it and can calculate the hash nothing else is learned street broadcasting it.

I think you are wrong , cause you cant know the confirmation time of the transaction ;) or could you ? thats just an example and i want more anything else ? :)

Thank you.

This is starting to sound a LOT like an XY problem (http://mywiki.wooledge.org/XyProblem).

http://mywiki.wooledge.org/XyProblem


Perhaps if you tell us what you are actually trying to accomplish, you can get some much more useful help.

My first guess is that you are trying to create a "game" where someone sends a transaction, and something about their transaction determines if they "won".  You don't want them to know if they "won" before they send the transaction.

There are plenty of games like this, and solutions for that sort of problem have been around for a long time.  There is no need to re-invent something more complex when the existing solutions work fine.

If you aren't trying to create a "game", then what exactly is it that you are trying to accomplish?  Why do you care if the sender knows their hash?  Why do you care when a receiver knows the hash?

May I know the solution you are indicating here ?

I'm not trying to make a game cause i'm not crazy to make a pure betting game where i might lose all my money.

But First you Said there are  plenty of games like this  i'm ready to offer you right now 1000$ and  i will send it to enscrow if you can give me just one site offering a pure game based on blockchain . if you cant than i ask you kindly to never user the internet again (if you are a man). read about the online games business stratigies . (You feel too smart ? anyways

i'm trying to learn about bitcoin payments and how they work for something out of your fast mind thank you .

Damn... You hit the wrong man. There are not many in this forum, who can help you like DannyHamilton.

He is trying to be smart in a crypted dick way    >:(

I dont know you. May be you are smart too. But, being spent more than a year in this forum, I can tell you, there are many smart guys in this forum and DannyHamilton is obviously one of them. Sometimes a bit harsh... I dunno why. But, he is known for his helpful nature across the board. So, you could just be polite to learn... anyways. It is your choice.

Yea i geuss you are right i'm closing this thread , and i apologize to him . But 1000$ is still On and anytime he can PM mE .

Thank you.

It is not smart to start a post with "I think you are wrong" when you do not know the answer yourself.

Anyway, knightdk is not wrong. A transaction hash is a hash of the transaction and nothing else. Once it is published, the data in a transaction does not change. However, somebody could take a published transaction and create an equivalent (but different) transaction that would have a different transaction hash.

AFAIK, satoshidice.com offers blockchain based gambling game.

HAHHAHAHHAHHAHAHHAHHAHAHAHHAHHA  You made my day (Go kill your self )   ;D

Go ahead.  Set up the escrow, and explain the conditions of escrow release.  I suggest using any of the following bitcointalk members to hold the escrow funds:

• John K.
• escrow.ms
• OgNasty
• Tomatocage

But you're unwilling to explain it?

I suggest that you start by learning how transactions actually work, then learn how hashing actually works.  Once you've got those figured out, you'll have a better understanding of what you're trying to accomplish.


I'll see if I can find the private key so that I an decrypt it.  I hate that I'm always encrypting that and forgetting about it.


Just let me know when you've got that escrow set up.

Plonk!

LMFAO :D

Plonk! is you and challenge is accepted escrow rules :

1 - You will send the same amount to escrow 1000$

2 - Escrow must confirm the payment and must be a trusted guy from this forums.

3 - Your site must be working and must be A PURE BLOCKCHAIN BASED GAME THAT I CAN CHECK IF I WAS TEACHED ON A BLOCKEXPLORER.

Like : Blockchain.info.

Or any other blockexplorer. and the game must NOT be based on transaction hash sens its can be calculated :)

Do you agreee ? if so please get a trusted escrow guy from the main page of trusted escrow services on this forum.


if you lose escrow must release payment to me if you win escrow release 1000$ to u.  :)