> Signal for example uses ephemeral keys for each message.
There’s a big difference between identity keys and session keys. It makes total sense to use lots of throw away keys (this is how tls works) but making a new identity key for every message is madness.
There is no empirical evidence for how frequently to rotate your identity keys.
A few years ago NIST started recommending never changing passwords unless they are compromised [0]. Identity keys aren’t exactly the same as passwords but I think they are similar.
I don’t think anyone quantifies how much of a benefit there is to changing your password nor how frequently to change it. “As frequently as possible” is not useful advice as that could be every minute or never. I need more actionable guidance so I can weigh it against other priorities