Outcast_Searcher wrote:But getting to 5000 or 10000 in a few years or even ten years seems COMPLETELY contradictory to the most aggressive expectations I found of IBM selling 50 qubit quantum computers in a few or perhaps ten years, if things go well.
Moore law may be applicable and this can result in huge surprises, how fast number of q-bits grow.
Also, per the same articles cited above and similar, 50 qubits would provide an extremely powerful computer compared to computers today. So I'm not sure I'm buying even the need for many-thousand bit quantum computers to break cryptography (with the right programming expertise).
Quantum computer can do only so much and not more as per given number of q-bits.
There are cryptographic approaches resistant to quantum computers with *billions* of q-bits at their disposal.
Read research article which I have quoted before for in depth analysis.
Here it is quoted again:
https://arxiv.org/pdf/1710.10377.pdf They are claiming that about
half a million of q-bits would be needed to intercept bitcoin payments in real time. My son believes that 5000-10000 could do but this is under ideal conditions (no decohherence related errors between other close to magical features), so it is a lower limit.
So 50 q-bits is surely far short of need.
There are mathematical problems far too hard to solve for even very powerful quantum computers and encryption is inherrently easier than decryption.
Actually I am aware of encryption method based on *quantum entanglement* which cannot be broken by laws of physics. Legitimate users of this method would also be aware by virtue of laws of physics that someone was tampering with their message, even if breaking the code was impossible in the first place.
Chinese military (and possibly other militaries too) are testing this method for communications.
So arms race between encryptors and decryptors will be won by the first lot.
Btw,
Quantum computers are unlikely to *ever* materialize in form of PC. Their circuitry need to work close to absolute zero to minimize decoherrence related troubles. Liquid helium cooling etc. It will be toys of military, big corpo and millionaries.
There are some suspicions expressed by Roger Penrose that emergence of consciousness might be related to quantum computing going on in your brain, but these are IMO speculations. You may read about Penrose-Hameroff ORCH-OR theory of consciousness if interested.