Topic: How many bitcoins can be produced in a single day? - page 2. (Read 14016 times)

Meh, they would make more from screwing over a single merchant with a double-spend than a lifetime of transaction fee extortion, and people would abandon Bitcoin in both cases.

The chain building must conform to the current network parameters, including difficulty. It must be built without leaking onto the internet at any point (slightly difficult), and if it doesn't match what the network expects when it is released, that would cause it to be rejected and all that hash power wasted.

Or something a bit more subtle.. like refusing to include transactions unless a higher transaction fee is paid.  Sure other people could try to mine them, but eventually, they'll be orphaned.

ahhhh, I see.  edit; But, how would they spend coins on our chain before overwriting the chain?

So the only other hurdle for them is building a chain to match the length of the current one before joining? Of course they can likely do this all at difficulty 1?

You don't know until it's too late. The attacker starts mining on a chain of their own, without broadcasting the blocks to the outside world. They could be 100 blocks ahead of us right now, and you wouldn't know it. On their chain they're still in possession of their bitcoins, while they spend them all on our chain. When they're happy with the fruits of their spending frenzy, they unleash upon us their chain, which is immediately accepted because it is longer.

Have fun cashing out.

This is where I fail in my understanding of the double spend.  Suppose someone gets the hashpower (costly) and goes through with this 'attack', wouldn't it be self defeating? I mean everyone can follow the transaction trees so they would know when/if it happened and at that point wouldn't bitcoin become completely useless as everyone loses trust and pulls out? The attacker only really has one attempt to profit on this before the house of cards falls down correct?

Or is it a case of blind denial and people will try to fix the attackers changes and keep bitcoin limping along even though the trust is now shattered?

aye, if they had 51% they definitly would not have a shortage of BTC to play with. ;p  And yea, the rolling back of a huge volume of transactions seems very concerning.

Between each difficulty increase, the network produces 2016 blocks. 


So if you've increased 3 times in 5 days, you've made 3x2016 blocks in 5 days.  That's 6048 blocks or 302,400 bitcoins.  Now you see why people are having wet dreams.

Remember that even with 51%, no attacker can spend your or others' coins. They can only spend their own, prevent your transactions from occurring, and roll back your and others' transactions at will. That last part becomes more and more difficult with the passing of time, and depending on how much hash power the attacker has.

Aye, so pretty much like I'm imagining then. Sooo, how many merchants are able to deliver a product before the blocks resume and the chargeback happens. I mean if the 51% is sustained long enough to be noticed by devs would we not be able to fork from it?

edit; don't get me wrong, I see the potential for this to happen with the 51%. It seems seems they would need too many others things to fall perfectly into place for it to work.

They wait with the "chargeback" until the merchant is satisfied with the amount of confirmations and gives them the product or service, at which point the attacker "charges back" the transaction and gets to keep both. There is no limit as to the amount of merchants they can screw over, so the potential for damage is huge.

aye, I get the concept. But wouldn't they need to receive something in return from the soon to be charge backed transaction to benefit from it?

Think chargebacks... for Bitcoin.

Yes. They would be mining on a worthless chain.

Thanks for that. It's been a while since I read any serious discussions on the topic. I would be fairly concerned about the transactions not confirming. This it would seem could be more devistating to the BTC economy than the potential to 'spoof' BTCs(sorry for the bad terminology. I'm still having a hard time grasping just how double spend would benefit the perp in the end)

edit; sorry for sidetracking the OP a bit. As RJk and others have pointed out the difficulty adjestment would correct the increased generation on its own.

The question was about how many bitcoins can be produced. If someone (be it Gavin or anyone else) releases a piece of software that generates more than 50/block + retarget for 2016=14 days, whatever it generates isn't Bitcoin.

The correct answer is: however many the developers code into the client. This can be changed, but right now we have no reason to believe it will.

Double-spending isn't spending to 2 merchants. It's spending to a merchant and yourself, or sending to an eWallet and yourself (e.g., send to an eWallet, wait until it is confirmed, withdraw and get some other coins, reverse the original transaction).

Or he can prevent any transaction from confirming.

>50% at the hands of a malicious entity really is pretty bad.

If some magical device came along that could do petahashes per second, keep in mind the following information: Blocks can be created as fast as your hardware will go, you could create 100 of them within 10 seconds if your hardware was that fast.

However, there are 2016 blocks per retarget interval, so the maximum number of blocks that could be created before the difficulty was adjusted would be 2016. Currently, that is BTC100,800.00 plus fees, at BTC50 per block. If you created all 2016 blocks within 1 day, the difficulty would jump in order to fix the generation speed.

But there is another factor to contend with: The difficulty cannot rise more than four times the current value per retarget interval - so the current value is 1726566.5591935 and four times that would be 6906266.236774. It would continue to rise in 4x jumps until the block creation rate was 2016 blocks per 2 weeks, as it should be.

Just for laughs, I'll use my 2016 blocks per day example for some calculations. 2016 blocks per day is 14 times as fast as the network wants to go, so at the end of day one the diff would rise at the max rate of 4x. Now that 2016 blocks takes 4x as long to create, it will be 4 days before the next retarget interval. 4 days is still 3.5x as fast as the network wants to go, so at the end of 4 more days the diff will rise again, but this time by 3.5x. Now, the diff is 14 times higher than it was 5 days ago, and the block creation time is now back on track to where it should be. Therefore, in 5 days of mining, the network has adjusted the difficulty to neutralize this hashing monster, and keep the block flowing at a steady pace.

The trick now is what happens when he stops mining. At that point, the network is 14x higher than it should be, so it could take a while to get back to normal....

P.S. If I have made any blatant mathematical errors, I'm sure the smarter folks here will helpfully point them out. Please and thank you