Quote from: BubbleBoy on July 06, 2011, 10:15:48 PM

Firstly I don't find any relevance in speculating what will happen in a few decades from now. The block bonus will stay above 12.5 BTC for the next decade, and it's entirely possible that bitcoin will run it's course during this decade and fail for unrelated reasons. This is the internet after all. I've expressed my doubts that the "mine for fee" model is sound from a game-theoretical perspective: it seems the users are incentivized to pay a fee as small as possible (maybe 1 satoshi) since there's no way miners can differentiate on the market.

Then we have a Bitcoin that will work (or not due to other reasons) for the next decade. I wouldn't be satisfied with that and I think as soon as people realize that Bitcoin is not 'for ever', they will not accept it for one decade either.

Quote from: BubbleBoy on July 06, 2011, 10:15:48 PM

For the purpose of our discussion, in the foreseeable future and without massive growth of the number of transactions, the main motivation of the miners is the block bonus. At current prices the block bonus is over 500$/block and all other things equal it should maintain that $ value even if it drops to 12.5BTC: the miners that don't hoard are the main source of liquidity and if they inject less BTC the price will rise proportionally. So in order to rent 50% of the network you need to pay at least 1500$/h

If all other things equal, block bonus will be about 12.6 (0.1 fees) * 15$ (current rate) = 189$ per block after the next decade. And if all things equal, it will be 0.1 (fees) * 15$ = 1.5$ per block in normal Bitcoin operation, after the coin generation phase.

Quote from: BubbleBoy on July 06, 2011, 10:15:48 PM

Secondly, you assume you will be able to amass this hashing power surreptitiously and use it repeatedly without being detected. That's not realistic. Honest miners are unlikely to rent you the hashpower since it's obvious why you needed it. Furthermore, if the average player is small, you will incur a high price in contacting many of them, and you will need to pay way above market rates to attract them. You will need to advertise and attract further suspicion upon yourself. It seems highly unlikely that your criminal endeavor reach the same economy of scale and efficiency the open network has. You will either build your own hardware, a capital intensive task, or buy it off the black market at very high prices in order to maintain discretion, from a handful of players (Large conspiracies inevitably fail). An hour of 50% hashpower will then cost maybe 150.000$, not 1500$

Assuming you finally get to 50%, using it for a whole day will quickly attract the suspicion of the community. It's not reasonable to expect to use it more than a few times without crashing the bitcoin price and halting most bitcoin trades. You can't double spend a few bitcoins many times, you need to double spend many bitcoins a few times in order to recover your fixed costs, and before your attack tanks the exchange rate due to panic.

If Bitcoin would be well accepted and a solid economy would depend on it, frauding a few Bitcoins wouldn't stop that. Either there's not going to be a solid Bitcoin economy or it will be feasible to double-spend some coins often enough to get one's investment back (and more).

Quote from: BubbleBoy on July 06, 2011, 10:15:48 PM

Quote from: Stevie1024 on July 06, 2011, 07:31:34 PM

One more question, what do you mean by: "as to not get caught"?

Assuming you manage to do all of the above and successfully double spend 1 million $ in BTC, the fraud becomes apparent quickly. If you buy a large house you will get caught and be indicted, I have no doubt about that. You need to launder the money quickly and maintain anonymity to pull a double spend. I believe it's much more effective to simply short the market and attack the network directly, assuming you have 50% hash rate (borrow BTC and sell out, then buy back in at pennies, no need be anonymous, just make sure the attack can't be traced back to you).

I don't see the need to do so secretly, isn't Bitcoin supposed to be 'not backed by law or goverment'? I'd not be committing fraud, I'd just be playing by the rules of the game!