If you turn off message key backup, all it means is that if you lose all your devices (and thus your keys), you will lose your history. Otherwise, if you have

If you turn off message key backup, all it means is that if you lose all your devices (and thus your keys), you will lose your history. Otherwise, if you have at least one device active on your account, it will receive your message keys and gossip them (if needed) with your other devices. You can always do a manual offline backup too for safekeeping as a workaround. > If I understand correctly, sounds like security is based on the complexity of your recovery passphrase and an implicit assumption that the passphrase doesn't get transmitted to the server... is that correct? If you use cross-signing, then yes - your signing keys are stored protected by the recovery passphrase on the server. We also support gossiping them between devices (same as message keys), and there's no reason for them to have to persist on the server. We just need to hook up the UI to expose that as an option and we ran out of time to do that before shipping the initial release. It will follow shortly.