Possible, but maybe far from certain.

Breaking the Enigma wasn't really smooth sailing.
It had its ups and downs during the most critical years,
but those can't be summarized in 100 words.
Also the Germans helped by overestimating the strength of the Enigma and thus neglecting some measures that would have been in their interest.

The Venona project is also instructive.
It achieved a lot and yet decrypted a small part of all intercepted messages.

@benroyce @jwcph @erikcats @signalapp

There's also the fact that every time so far that some company has claimed "quantum supremacy" and boasted of having "solved" a certain precisely-chosen problem multiple orders of magnitude faster than possible with a classical computer, a different set of researchers have looked at that problem, reframed it, and come up with a way to solve it in comparable time using a classical computer.

The level of hype really is staggering.

@zakalwe @paraw @jwcph @erikcats

there is no lock made by a human that another human cannot break

@mkj @erikcats
yeah that's my understanding as well

"you can break this but you need a bank of 1 billion computers operating for 1 billion years, so..."

{quantum computing enters the chat}

"oops"

so you just change the method to something that is not so vulnerable to quantum computing

Bottom line, I guess, is that there are plenty of nuances here which I am happy to let people who know the stuff much better than I do handle; but it's not quite as clear-cut as "the whole world will break" as it is sometimes presented.

There's a number of detail assumptions which may or may not turn out to be true which impact the actual result. But taking a cautionary stance, we do know that the risk is non-trivial and thus taking mitigative steps is good.

@benroyce @erikcats @signalapp

@mkj @benroyce @erikcats well, one other problem is that of the immense number of continuous parameters needed to describe the state of an actual quantum computer. And then along come papers such as this one
journals.aps.org/prresearch/ab…

This is really cool! And the way I see it, it has the potential to address the problem above by providing a general way to discretize quantum systems. So I guess we'll have to wait and see how things work out.

Personally, I'm quite sceptical about the whole quantum hype, but I'm keeping an open mind.

@paraw Oh, there is a *LOT* to this which doesn't fit in 500 characters! And like I said, I'm not an expert. But we DO know that this stuff is possible in principle, even if not in practice currently; and we DO now have primitives which provide protection. Since it's hard to change the past, taking a cautionary stance would mean that we move toward a setup which provides protection while not stripping us of protection, while there's time to do it less stressfully.

@benroyce @erikcats @signalapp

To my mind, quantum computers these days are maybe perhaps at the level of EDSAC, ENIAC or their ilk in classical computer terms: just barely usable for more than proof of concept. No one familiar only with those would imagine them being developed into a smartwatch yet here we are. We can see that there are certain classes of problems, widely relied upon, where quantum computing significantly changes the rules of the game. Not a crisis, but worth attention.

@paraw @benroyce @erikcats @signalapp