Can someone smart explain how quantum computing can help AI? I don’t know much about quantum computing, but wouldn’t you be able to better simulate a brain with quantum computers?

Some people, notably Roger Penrose, think that the conscious experience of understanding is non-computational and a result of quantum systems made possible with micro-tubials within the brain. However, no real model for how this would work has been put forth, so I don't believe quantum computers are projected to better simulate brains.

If it’s 1000 true qubits, won’t that be strong enough to break bitcoin?

The amount of hype in this field is beyond too much.

Although a stunning achievement in its own right, this does not really help us. Like at all.

People thinking we are gonna scale up to a million plus qubits in a superconducting modality is delusional.

Think of the secondary infrastructure needed to do that. Untenable.

It blows my mind IBM is dumping so much money into SC qubits when trapped ion or neutral atoms would scale much better.

to my knowledge encryption standards like AES are not yet broken by any computing, only via bruteforece i.e. the math is still holding up

but the crowd within IT-Sec yelling 'quantum computing is killing encryption' is getting louder every day

I am not smart, but possible AI use for QC:

1. AI could optimize quantum circuits
2. it could help with debugging QC-systems
3. assist with analyzing big data from QC
4. develop QC-specific algos

Number of qubits is not the only parameter of a quantum computer. Other are qubit lifetime, gate fidelity, gate operation time, connectivity.

And, no. Even 1000 perfect qubits aren't anywhere near enough to break SHA-256 (which underlies bitcoin security).

With 1000 perfect qubits you can crack RSA-256, which could be cracked classically since 1990s.

You're right that symmetric cryptography (like AES) is still safe against quantum attacks, but the Internet relies heavily on asymmetric cryptography protocols, as well. The latter are based almost exclusively on the (elliptic curve) discrete logarithm problem and the integer factorization problem, which are easily solvable on quantum computers, so they wouldn't be secure in a post-quantum world.

The problem is that symmetric protocols need encryption keys, which can't securely be exchanged over insecure channels (like the Internet), so you either need to exchange them out-of-band (infeasible in most cases) or in ways that rely on the difficulty of solving hard mathematical problems. Additionally, things like digital signatures (which are vital in systems like Bitcoin) always use asymmetric cryptography, so it being broken would make it impossible to check the identity of the author of a digital message.

Luckily we've been working on post-quantum asymmetric protocols that use new mathematical problems for which we don't yet have efficient quantum algorithms. The hope is that by the time large-scale quantum computers become widely available, we'll have minted new secure standards.

Great answer! Just one note: you wouldn't necessarily need to break SHA-256 in order to break bitcoin, you could also just break ECDSA, which would allow you to spend any bitcoin in any wallet. This is possible with a large enough quantum computer, though you would need significantly more than 1000 qubits (in the hundreds of millions).

They can be used to train neural networks many times faster than what is possible with conventional computers.

To train a model, it requires a lot and a lot of parallel computing, this means that each operation is very simple and disjoint from one another but the shear volume of computation needed is too expensive for the current hardware. Quantum computer can use superposition to concurrently compute every operations at the same time without needing any extra cores. This is extremely valueable as training will now only takes seconds as opposed to days and the cost will be around 10$ as opposed to thousands of dollars.

This is from my own understanding so it might be incorrect to some extent.