Saw a comment on a banking thread that said that Quantum Computing will kill crypto, I assume because it would be able to edit the blockchain and thus killing the entire point of bitcoin, but how exactly would it do this? How does it work and why does it mean all current encryption would become useless?
You're viewing a single comment thread. View all comments, or full comment thread.
Comments (25)
sorted by:
The theory with quantum computing is that rather than have to calculate millions or billions of possible keys and check each one in turn to see if you've found the correct one, you simply point your quantum box at the task and it calculates all possibilities simultaneously. You then simply pick out the one that did the trick.
Not really. Going single-core to multi-core each core is still calculating one key at a time. This means it's not terribly difficult to simply crank up the key length - add 8 bits and you've got a thousand times as much work to do, which makes the gains from running 8 cores diminish somewhat.
Similarly, GPUs, while offering substantial parallelisation, merely move a balance point that can be redressed by using longer keys.
The point with QM is that you run all of the numbers at once. As I understand it, a lot of the cleverness is in the "simply pick out the one that did the trick" step, as otherwise, yes, you are just running through your impressively-calculated solutions one at a time.