YES. We need Let's Encrypt but for personal communications.https://twitter.com/matthew_d_green/status/806135647199252480 …
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Signing your new key with your old key + gossip protocol is enough. No need for common ledger. I want a social substrate anyway.
I think you want some sort of concrete record about the key changeover, putting it certifiably in the past.
…so that if a past key is compromised, an attacker can’t just publish “I’m using this new key, X now!”
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