Egregoros

@feld there are about eight hardware modalities for quantum computers right now; only some of them require superconductivity. There are also a great many real-world problems to be solved with quantum computers that have nothing to do with factoring large integers; breaking RSA or ECC is probably not even in the first five major breakthroughs that we will see. I think it’s important to keep in mind that the reality of quantum computing as a paradigm is very much distinct from whether or not someone can spoof a DSA signature or break your TLS 1.2 traffic in something approaching real time.

The problem is, we have been seeing for the last 10 years a series of exponential growth inflection points when it comes to quantum computing capability, and we usually cannot see that those were inflection points until they are in the rearview. Almost all of them were also not in areas that experts had previously predicted we would see breakthroughs.

The other problem is that transitioning the entire installed base of cryptography on the Internet to new standards is something that will take many years of effort. If we wait until we are reasonably certain that Shor’s algorithm at scale is around the corner, we have waited far too long to mitigate that business risk.

I would refer you here to Scott Aaronson’s blog post from a few weeks back; he is both well respected and not prone to hyperbole: https://scottaaronson.blog/?p=9718