xpubs of npubs on Nostr
DM-only Nostr app. Users trade deterministic npubs. Each message between the users uses npubs only once. No address reuse.
This would help with some of the DM metadata leakage on Nostr I think.
Discussion
Yeah instead of press a 'recieve' button on a Bitcoin wallet, you press a 'generate npub' button, and it does.
Easier than that. If I provide you with a deterministic npub, you can have a DM client that uses a new one each message and it would know to keep all those in one chat.
And the initial npub trade can be done over normal DM channels. It would be similar to payment channels at least as far as the UX is.
Click a button "Open Ultra Secret DM" with a user. Deterministic npubs are exchanged, then chat commences using 1-time npubs.