[CatMustard]

> it won't be a big deal.

This isn't a space I know too much about, but even if we all start using quantum-safe encryption for everything today, won't the arrival of quantum computers that can break traditional encryption not still be a big deal?

Given that intelligence agencies, tech companies and various bad actors have been storing encrypted data for a long time, hoping to decrypt when (if?) that day comes?

[utopiah]

Sure it's still a big deal but it's not as if suddenly everybody get a quantum computer and can use it nilly-willy. It will be (or is) scarce enough that information has to be selected as critical in order to be deciphered a posteriori.

The time between the moment the information is recorded and when it's deciphered is what matters, rarely the information itself abstracted from all context.

So even if suddenly having a classical cryptography is broken, trivially, then there still need to be a way to search through it.

Typically for a random person that means their credit card pin and their email password for example. Well, you chance that and if, say the NSA, can decipher your old email password even 1 minute after you changed it, no big deal. If they can decipher your old emails it might be a big deal but probably not. I would argue it depends on actionable information (e.g. a coup happening tomorrow) and legal information (e.g. the proof that a certain person was an informant and should be extradited).

So... I would argue historically, huge deal, daily life... probably not much for most.

[parsimo2010]

Intelligence agencies and companies for which industrial espionage is an actual concern will re-encrypt their data storage, or have already done so. The only risk is on data that was already obtained with a vulnerable encryption. So there is some risk that a few secrets are lost, but it won’t be everything. And if you were to start now and quantum decryption isn’t viable for a decade then any secrets that do get exposed are surely less of a problem than if they were discovered today.

[BoppreH]

Definitely, but then the damage is limited to the encrypted data that those actors managed to intercept some years before. Compared to QC arriving to an unprepared world, that's a very limited impact.