4 ms·

"In order to fake a transaction, you would need to control 51% of the total hash rate of the Bitcoin network, which is impossible." Impossible?! The claims ab

"In order to fake a transaction, you would need to control 51% of the total hash rate of the Bitcoin network, which is impossible." Impossible?! The claims about why this polynomial-time attack on Bitcoin is not really a problem seem to get more outrageous with each passing day. I find it interesting that you simply assume that there is no other attack on Bitcoin. There is no proof of this. There is not even a good enough definition of the security goal of Bitcoin to allow for such a proof.

notaddicted 14y ago
Call it economically improbable. Right now you could maybe get 51% with a 10-20 million dollar investement in ASICs. If you took control of the network and started forging transactions, bitcoin would no longer be useful and all those coins you stole wouldn't be worth very much. EDIT: I vaguely remember the Linode hacker mention that a more reasonable attack possibility would be if you slipped an backdoor into the popular bitcoin client libraries, and then it could be used to steal. edit2: spelling.
- betterunix 14y ago
  Maybe you only want to deny confirmations to your enemies. I can imagine that the US government might want to prevent people from making donations to Wikileaks. Maybe someone just wants to destroy Bitcoin, for reasons that are beyond your imagination. Really though, trying to figure out your attacker's intentions or goals, or their willingness to commit resources to an attack, is a fool's errand. This is even more so when your system has known and exploitable weaknesses. The Germans learned this lesson the hard way with Enigma: https://en.wikipedia.org/wiki/TICOM https://en.wikipedia.org/wiki/TICOM
  - notaddicted 14y ago
    I guess that by "Godwin's Law of Nazi Analogies" this discussion has officially run its course :P. I think I agree with the major implications of what you are saying: bitcoin hasn't demonstrably withstood nation-state levels of attack effort, so calling anything impossible is premature. If the bitcoin network survives for long enough [which can't be taken for granted] this will eventually happen, but it hasn't demonstrably happened yet.

notaddicted 14y ago

Call it economically improbable. Right now you could maybe get 51% with a 10-20 million dollar investement in ASICs. If you took control of the network and started forging transactions, bitcoin would no longer be useful and all those coins you stole wouldn't be worth very much. EDIT: I vaguely remember the Linode hacker mention that a more reasonable attack possibility would be if you slipped an backdoor into the popular bitcoin client libraries, and then it could be used to steal. edit2: spelling.

betterunix 14y ago
Maybe you only want to deny confirmations to your enemies. I can imagine that the US government might want to prevent people from making donations to Wikileaks. Maybe someone just wants to destroy Bitcoin, for reasons that are beyond your imagination. Really though, trying to figure out your attacker's intentions or goals, or their willingness to commit resources to an attack, is a fool's errand. This is even more so when your system has known and exploitable weaknesses. The Germans learned this lesson the hard way with Enigma: https://en.wikipedia.org/wiki/TICOM https://en.wikipedia.org/wiki/TICOM
- notaddicted 14y ago
  I guess that by "Godwin's Law of Nazi Analogies" this discussion has officially run its course :P. I think I agree with the major implications of what you are saying: bitcoin hasn't demonstrably withstood nation-state levels of attack effort, so calling anything impossible is premature. If the bitcoin network survives for long enough [which can't be taken for granted] this will eventually happen, but it hasn't demonstrably happened yet.