Martti Malmi on Nostr: I haven't done groups yet, but we can do it like signal: Group members send their ...

I haven't done groups yet, but we can do it like signal: Group members send their group-specific Nostr public key & symmetric decryption key to all other users in the group. Rotate key now and then, at least when users leave the group.

Also for multi-device use we can do like Signal: have multiple double ratchet sessions with your own devices and devices of others, send to all of them. https://signal.org/docs/specifications/sesame/