This post-quantum crypto thing is ridiculous.

Given that presentation's analogy with giant siege artillery as the "headline-grabbing attack of 80 years ago" that turned out to be a technological dead end, combined with it belittling modern quantum computers as "physics experiments", I can't help but think of another physics experiment that resulted in an even more headline-grabbing attack 80 years ago. An experiment that cost the equivalent of $30B and employed a hundred thousand people, and took so long that the original enemy had already been defeated, and when it was finally used it wasn't much more deadly than the regular bombing campaigns they'd been doing for years.

But that one wasn't a dead end - as a direct result, within a couple of decades there were 40,000 nuclear warheads, individually up to 3000 times more powerful than the first, and collectively a million times more powerful, which completely changed how everyone had to think about national security.

Technology development is not linear over decades. There are linear phases, exponential phases, sub-linear phases, step changes, sometimes it goes backwards. You can't (as that presentation attempts) take two data points and extrapolate. You can't guarantee quantum computers will break encryption in the near future, but you can't guarantee they won't either. Given the significant impact if they do, I feel it's worth putting a modest amount of effort into preparing for that possibility, rather than (as seems to be human nature) sticking our head in the sand and then scrambling to react when it's already too late.