> Rotating keys for deniability. That's only needed if you sign with those keys. DKIM for instance. If your protocol is based on key exchanges (as Signal is),

> Rotating keys for deniability. That's only needed if you sign with those keys. DKIM for instance. If your protocol is based on key exchanges (as Signal is), you don't really need to rotate anything, because recipients can always fake messages coming to them. (Group discussions however may be another matter.) That said, there are other reasons to rotate keys, typically to diminish the probability and the impact of leaks.