Quote from: crwth on August 28, 2019, 04:11:06 PM

Quote from: 2double0 on August 28, 2019, 12:38:08 PM

Why not find out a technology that can prevent us from the attacks of QC? If QC and other things were imagined and have become truth now, there must be something that can abolish their twitches and burst the bubble before it becomes too big to stop you from breathing.

Approaching it where the problem is QC (theory only) it should be answered by the same powerful thing, QC. Its like fighting fire with fire, but everything is digital.
We are not there yet where its applicable already.

I would not so optimistic about QC. The main problem of their realization, is the problem of symmetry. FT transformations (its composition of Fredkin gate and Toffoli gate) will destroy quantum entanglement in bosons. "raw" fermions can't be used for QC too because, if we have more than 3 qubits, than their result vector will be 0, so we can't calculate anything with it.

As i read last time, scientists want to use "fermionic lattices" . But it will be really hard to impelement it in real technology, because it much harder to control such "lattice". In "lattice" you need to control n states in n qubits, but in "raw" QC without such lattices it would be enough to control just 2 states in n qubits.

And for "ECDSA hack" we need thousands of qubits (and now have just a 50 qubits, after 40 year of QC research start).

Quote from: figmentofmyass on August 22, 2019, 09:42:16 PM

my understanding is that ECDSA will eventually be vulnerable to quantum computers. SHA-256 not so much.

You're right. But let us be more specific:
Every public key cryptography is vunerable to quantum computing due to Shor's algorithm (for integer factorization and discrete logarithm). SHA 256 is not vunerable in meaning that there is not any quantum algorithm which breaks it fast. But it's vunerable in meaning that quantum computers may be incomparably powerful (in million times) compared to today's computer.

Also, it's interesting that we don't have any quantum computer for now (and i doubt that we will have one, with all it's "magical" capabilities) but we already have post quantum RSA