We have a pretty good idea. Post-quantum crypto is a real thing. There are conferences in the field about it.

Certain classes of problems are shown to be faster on quantum computers. One of them is factoring prime numbers, which is what our public key crypto is based on. Traditional block ciphers are also somewhat vulnerable, with their security is effectively cut in half. In other words, a 256 bit key is as secure as a 128 bit key. That solution is easy; we double the key size and call it a day. Public key crypto, however, is a bigger problem. Needed whole new algorithms.

The big unknown is how powerful quantum computers will get. It’s going to take a lot of qubits to break public key crypto. It may be completely unfeasible to juggle that many qubits in superposition. It’s also possible it will only barely do it, in which case we can also increase the key size and call it a day. But post-quantum crypto is being worked on, just in case.

Zoom is still bullshit. Their software has had all sorts of problems that don’t need QC to exploit.