Bitcoin Forum

that means they can get 100% proof of stake in PPCoin

Eh, don't worry they won't need quantum processing power, they already have plenty of power to do it.  I'm sure that it would just take a few less phone taps a day on the classified NSA supercomputer in Utah.

they'd have to not get caught because right now, with the NSA leaks, large governments are not looking too people friendly.  

I suspected in 2001 the NIMDA internet infection (https://en.wikipedia.org/wiki/Nimda) was a government attack due to the incredible level of sophistication at that time.  But, when I analysed it for a week, the "heartbeat" came from IP addresses allegedly coming from North Korea.  Doubting that North Korea could possibly launch this sophisticated of an attack, i suspected that the government doing the attack was smart enough to pick a scapegoat.  

so, in the scenario you describe, the question is, how will they create the scapegoat?  
  

Plus, in this and other scenarios, the countermove would be to branch the blockchain to that moment before the attack.  Valid transactions during the attack would be rolled back.  So, there'd be collateral damage.  But, the vast majority of the blockchain would be protected.  
 

by mining curecoins and prime95 instead of quarkz

not following.

to clarify, the "scapegoat" is the entity that the real attacker will try to pin the attack on.  E.g., the NSA does it in such a way so that it looks like North Korea is doing the attack. 
 

So?

I think you have been watching too much Power Puff Girls.

No 51% style attack is an unmitigated disaster unless it is coupled with a method of infecting and modifying all known copies of the blockchain.  Wake me up when that happens.  It could halt the system for a time though which would be highly damaging.

What would really suck would be some method of regenerating private keys (via something like a high percentage of fautly PRNG's coupled with backdoor'd crypto weaknesses and much processing power (quantum or otherwise)).  Something along those lines would probably spell the end of Bitcoin-I since it would attack the existing value stores.

Quantum computers are not yet a reality for the U.S government, or for any other government.

Yeah!

For god sakes, stop getting paranoid. There are plenty of problems before even considering this.

Actually I wonder why some are so afraid of possible 51% attack.

Let's imagine.. If I had 51% of the mining power... why would I destroy a gold mine producing me 1800 BTC / day. That would be over 1M $ / day.
If I were stupid enought, after I had used that mining power to destroy BTC and those 1M daily incomes, the hardware would be useless. NO WAY.
I'd rather keep mining.

Yep, that's more like a threat to bitcoin. Very unlike anyway.