Looks vulnerable to me.
Give me the budget (or ability to get loans) of the USA government or a national bank and I could kill Bitcoin... money back guaranteed.
Due to the economies of scale ASICs bring to the table, although the Bitcoin/Litecoin network is less vulnerable than it has been in the past, it is still rather vulnerable if someone were to throw a lot of money at attacking it.
no. that's mighty talk from you there.
first off, gubmints don't have unlimited resources for something like this. sure, they print money to save banks; but not all banks and not with unlimited funds. this is an entirely different animal w/o a sure outcome for them.
a gubmint's mere entry into the asic market would set off not only alarms throughout the Bitcoin space but also jack the price of all asic components to the moon to the point where it would be prohibitively expensive for them to produce enough equipment to carry out such an attack, let alone get off the mark trying to do so. and we would find out about it ahead of time. wait times are a couple months at most high capacity chip makers. any sudden delay in delivery would call for investigation. it would be impossible for a gubmint to make such a huge asic order w/o ppl finding out and w/o chip makers jacking their prices to the moon. the gubmint would be competing with the likes of Intel and IBM for chip runs.
then, there would be the political fallout, especially if they fail. try pissing off a few billionaires, like Branson or Ka-Shing, whose investment you'd be messing around with. you and/or a gubmint would end up in court in a nasty legal battle for damages. class action suits would be carried out by now wealthy early adopters.
then, there are the technical out-maneuvers that could be introduced into the protocol after finding out about such a plan and a brief pause to implement them. a change could be made to SHA 516 as an example.
and so what of a 51% attack that could be shutdown relatively immediately? there would be a temporary disruption of the network but then we would adapt and the gubmint would have wasted billions for nothing.
no, i think we are in a Pure Strategy Nash Equilibrium.
You are talking out of your ass here....
1. Yes, they have plenty of money to attack Bitcoin
2. If they were to do so, they wouldn't alert the Bitcoin community about it and give them a warning. It would be top secret & confidential. ASIC chip foundries work under under strict confidentiality agreements... If you don't believe me, then go tell me the status of BFL's latest order and report back. The government has the money and people smart enough to do all assembly and PCB work done themselves.
3. Bitcoin would not be able to respond quickly enough, as the government would already have 51%
4. Political fallout... Lawsuits... Governments pretty much do whatever they want. They always have and always will. If they see Bitcoin as a threat to national security, they can justify their actions.. Even if they don't truly believe this (see: weapons of mass disruption in Iraq). It wouldn't help that u would have to go through THEIR courts to sue THEM... Tell me how that works out for you.
5. A 51% attack cannot be shut down 'relatively immediately' and all confidence in Bitcoin would be lost due to all the things the attackers could do.
6. It could be done for much cheaper than a billion dollars by rooting mining pools.