What if, one day, someone equips with quantum computer + smart can figure out the private hashes in anyone's wallet base on the public BTC record?
Would the BTC become completely worthless immediately?
Re:For Sale: 29,656.51306529 Bitcoins
by LeoPanthera on Thursday June 12, 2014 @11:03PM
(#7887261)
If it happened overnight - perhaps.
But the algorithms behind Bitcoin are agreed on literally by consensus, the clients in the network which reach a majority are in control.
If it became clear that something in Bitcoin was about to be broken, the algorithm could be changed to something more secure, if a majority agreed.
Past transactions would not be affected - they are immutable - and new ones would become safe.
It would also depend on the economics of said quantum computing. But yes, I'd expect the value to decline because one could not guarantee their currency anymore. Similarly if someone invented a teleporter that targeted US currency, it'd become worthless because a thief could just teleport it out of your pocket.
What exists with BTC is 21 million or so unique valid hashes and no others can be created. With money, say USD, there exist trillions and no guarantee that some party (the government) will not create massive amounts of additional units.