If that were possible, we could just stop using nostr. It would require for secp256k1 elliptic curve cryptography to be fundamentally broken. (Or a client would have to issue many identities using a b...
Still not sold , contacts are something very personal and protecting it with only nsec which is static would be dumb , if the app implementes 2fa like for login and decription require nsec and then requir another password or passkey to open the file would make sense and become nsec is the account as well as a protection layer the user will not feel he is using 2fa
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