Logging into Keychat with your microblog ID allows you to receive Nostr DMs (NIP-4, NIP-17), but this is just a supplementary feature. We recommend using a new ID on Keychat—one that is completely unrelated to your microblog account.
Signal and MLS protocols generate a new encryption key for each message and delete it after use. This makes both protocols stateful, with the state stored only locally. In contrast, NIP-17 messages use a static encryption key that doesn’t change, allowing any client to decrypt past messages upon login.