Super interesting, hope others comment on the feasibility of this

This. A revoke key. That allows old key to be marked as old a set a new one.

And possibly copy everything from the old key to the new one, including followers and following.

What blocks the attacker to go back in time and publish a second pubk B? How do you know which event to trust if you have two of them?

Couple of solutions could be 1 Relays relaying meta data about when they received it. Means bigger nips. 2 Relays not accepting 'declaration of successor' more than 7 days old. Not sure if this needs a nip.

What if you are using the Gossip Model (Auto finding relays) and the attacker gets a hold of your keys, changes your relay to their custom relay and remove those protections?

I think easiest is to block successor events that are older than 7 days. I could do this on nos.lol with plugin. Anybody can query it then to find the earliest successor event for a given pub.

The problem with having a backup key to revoke your private key is that you have to keep it somewhere. We're already discussing an event where your private key has been stolen. Chances are you kept your revoke key in the same place as your private key: on the computer that was just hacked. Everyon...

I get what you're saying and you're right that the problem is people, but you need not only a way to delete your old npub but also claim your new npub, the revoke key could be a password chosen by you, like in bitcoin, you can have your seed phrase+pass. Another option could be social recovery but y...