Bitcoin Forum

I know you're calculating hashes, that need to fit in to a predefined set of rules. I know that this hash needs to be based upon the previous block. What I don't know is how this correlates to "confirming a transaction", which is what I believe the mining to be the point. Am I missing something in this picture?

Seriously, noone?

After finding the right hash a block that contains transactions is created and added to the end of the blockchain. Those transactions now cannot be reversed and people can't double spend.

Just go here:

https://en.bitcoin.it/wiki/Confirmation

When a hash is submitted that "solves" the block, then it is basically 1 of the 6 confirmations.  Since the average block time is supposed to be 10 minutes, this makes a fully confirmed transaction 60 minutes.

Most sites that allow you to spend Bitcoin will credit you after 1 confirmation, but some might go much higher.

There isn't a thing like 6 confirmations. That number is an arbirtrary one. You need one confirmation for the transaction to be confirmed and anything else above that adds security for orphan blocks, network attacks etc.
6 doesn't mean anything else than that your transactions are more secured from having 5 confirmations and less secured from having 7.

The block is basically a list of new transactions (new as in since the previous block). Each transaction is already confirmed in one sense - it has the signature of the owner(s) of the bitcoins that are going into it (i.e. the signatures of whoever's spending in that transaction). But this is only one level of confirmation - confirmation that, up to the last block, those signature owners still had those bitcoins. The problem would be that those owners could spend the same bitcoins into more than one transaction. That's the point of the blockchain; it creates one uniquely valid version of history - the only valid transaction history is the one in the longest chain of blocks. If two different blocks are created simultaneously, with the spending happening more than once, one of those blocks will become "orphaned" and ignored.

Helping?

Truth.  I'm just going off of an explanation that could correlate to the Bitcoin-qt wallet that shows "broadcasting" and then 0/6 confirms, etc.  It keeps getting confirmed everytime a block is found.

I guess it's just hard because a "simple" explanation of how Bitcoin operates doesn't really exist.  lol




This is much more eloquent.

Helping a lot, but the problem I have with that story is that the blockchain, basically, is a series of hashes. A hash, being an irreversible operation, doesn't tell you anything about the state of accounts. It's possible to put the information into the hash, but impossible to get it out of it. How in the hell do you verify that an account has x amount of BTC?

You hash the block header to create the block but the block contains all the transactions in a readable format.

I came across this video recently which explains how Bitcoins work. It's a pretty clear, simple, but thorough explanation of Bitcoin. Maybe it'll help you. I can't seem to post a link right now  but search for "How Bitcoin Works Under the Hood" on YouTube and you should be able to find the video.

there is a good video on vimeo at the moment https://vimeo.com/63502573 that gives a very simple explanation

You can post a link. You just can't have it in your signature until you have 10 posts.

This actually is a VERY good video. It appears I had the wrong idea of what exactly a block is :)

Thanks!