I'm not familiar with what cryptography Nostr uses here
We're currently trying to move away from https://github.com/nostr-protocol/nips/blob/master/04.md which uses symmetric encryption with AES-256-CBC (absolute trash compared to industry standard) to https://github.com/nostr-protocol/nips/pull/746. NIP44 just got audited.
But like @ekzyis mentioned: there are famous examples with RSA where weaknesses emerge when using the same key for encryptions and signatures.
We're currently trying to move away from https://github.com/nostr-protocol/nips/blob/master/04.md which uses symmetric encryption with AES-256-CBC (absolute trash compared to industry standard) to https://github.com/nostr-protocol/nips/pull/746. NIP44 just got audited.
Thanks :)