[bawolff]

> "I don't know of any long-lasting secrets" ≠ "There is / will be no need for long-lasting secrets"

This feels like a bad argument for religion.

The point though is not that i don't know any but that i can't concieve of any. I can't even imagine such a scenario, even hypothetically.

[Jedd]

Sure, but that inequality of meaning would have to lead to a 'Therefore I conclude this specific, highly infeasible, self-contradictory secret exists' - which is perhaps a common problem with arguments for religion.

I'm confident there's fairly mundane multi-generational secrets, without having to summon the illuminati or knights templar. Either way it doesn't negate the interest in having a technology that could provide that.

[bawolff]

Cryptography isn't a technology for keeping secrets, its a technology for keeping secrets in transit. Its not particularly useful for keeping multigenerational secrets (how do you do key management over 100 years?)

[Jedd]

Is your suggestion that key rotation is a necessary requirement?

I feel we're coming full circle towards the original discussion about pqc.

(Also, I feel cryptography is very much a tech that can assist you in keeping secrets at rest.)

[bawolff]

> Is your suggestion that key rotation is a necessary requirement?

If you want your secret to last more than one human lifetime, you have to enroll new people into the system somehow.

My main argument would be that cryptography is mostly useless in such a scenario. It makes much more sense to put the secret in a filing cabinet, put a lock on the filing cabinet, and if you are really paranoid, maybe hire some people with guns to guard it. Cryptography for such a scenario is the sort of thing that happens in movies not real life.

And even if cryptography was used, it doesn't seem like public-key would be very applicable at all, so pcq is extra irrelavent.

[Jedd]

Concur that PK is probably inappropriate, but not necessarily that this means PCQ would be (irrelevant).

The Voynich manuscript is likely a despairingly poor example of any argument, but it's the most famous long-lived / unresolved encoded text I could think of. (I think a year or two there was a claim it was properly decrypted but I'm not convinced it ever will be, mostly because I suspect it wasn't ever meant to make sense.)

Back to the key rotation question - I think we agree that's not a necessary requirement.

[bawolff]

> Concur that PK is probably inappropriate, but not necessarily that this means PCQ would be (irrelevant).

PCQ is almost exclusively about public key crypto since traditional symmetric crypto is already quantum safe (with a caveat that you might need to double key lengths to reduce risk from grover's algorithm)