Exchanges do indeed use Pay to Public Key Hash, but and it is a big BUT. Most exchanges reuse their addresses and so their public key is visible, and hence they are NOT safe from quantum computers.
All top 5 bitcoin addresses with the largest balances have reused their addresses and hence their public keys are visible. That is more than 600 000 bitcoins. 3 of them are multisig addresses, but even those can be cracked by quantum computer if the public keys are visible.
I would d prefer that exchanges would not re-use their addresses.
That is indeed the biggest problem right now. I do assume that exchanges will get their shit together once Quantum computers get feasible in a big scale, but on the other hand there have been exchanges that didn't even do transaction batching until just recently. At least in theory it shouldn't be that hard to avoid address reuse though, even at the scale of nowadays exchanges.
Well really disagree you on this point, Quantum Computing has ability to break the chain of today supercomputer in fraction of seconds and can easily surpass the block-chain too.
Bullshit and misinformation. Quantum computing will be able to solve some math problems faster than traditional architectures, that still doesn't make them a magic devices that instantly derive private keys from public keys or can "break the chain of today supercomputer in fraction of seconds" whatever that may mean.
Also the article shows complete misunderstanding of how mining works:
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Traditional computing reaching its physical limit is actually one of the reasons why quantum computing is being heavily researched in the first place. Accordingly we can expect more and more funding being poored into R&D for quantum computing (and other approaches such as neuromorphic computing) as improving traditional architectures becomes less and less feasible.
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I don´t necessarily disagree with this claim, but not everything that is heavily researched also produces the desired results.
The treatment of various lethal diseases is also heavily researched and still there are various illnesses that can´t be cured
using current medicine. Maybe quantum computing will run into similar problems as the traditional computer architecture and
the situation won´t be much different in a few decades than it is now.
Oh definitely. I'm not saying that quantum computing is bound to come into fruition, I'm just saying that the
same physical limits (ie. size) that affect traditional architectures don't affect quantum computers -- pretty much by definition.
Besides, it is likely that even if quantum computers become a reality at some point in the future that cryptography will
have also improved.
Candidates for quantum resistant cryptography already exist, it's mostly a matter of standardization and deployment. The latter possibly being the largest challenge.
