Fatman3001
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Make Bitcoin glow with ENIAC


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May 12, 2016, 10:21:58 PM


I disagree. I think you give the writer too much credit. A natural reading of what's written is that it is impossible to break Bitcoins algo in this universe.

Quantum mechanics is very much part of this universe.

Disclaimer: Not even an armchair scientist.

The threat from QC is that Grover's Algorithm greatly reduces the space you need to search for solutions.  It is impossible to brute-force a problem with 2^256 solutions, but it is a lot easier if you can effectively make the problem smaller, and that is what Grover's algorithm does.


Mmmmkey, what's your point?

That QC algorithms can make problems solvable that were previously unsolvable with classical computing.  A problem that would require potentially 2^256 attempts to reach a solution would be impossible to ever solve, for the reasons illustrated in the image above.  If you can reduce the number of computational steps to 2^128, or 2^64, it starts to become very possible.

Actually, it would be a lot more accurate to say that Grover's algorithm is one of the threats, not the threat.


Ok, I thought you disagreed with me. It's fascinating stuff that opens up a whole new world of possibilities. A bit annoying that one of those is to break Bitcoins security. I hope they can wait with switching the algo until crypto has found a reliable PoS system.