I’m self hosting both too. MollySocket’s docs are pretty clear that it never gets an encryption key for your account, so it can’t read your messages. It only gets/forwards alerts that something happened on your account AFAIK. So I’m not sure what data it has that’s worth encrypting.
For Signal/Molly, it’s less that the notification is encrypted as I understand it. It’s more the notification content is just “Hey! Stuff happened” for Signal. The app then reaches out directly to the Signal servers to see what’s new. So the message content is never sent via the push notification service (UnifiedPush or Google’s service).
That would require a lot of data privacy concerns to be addressed. Even if it’s an explicit opt-in. The current method uses sample text which can’t include PII. Using user supplied text would almost guarantee they’d get names and other PII in their data set.
I also imagine it’s harder to train the model when you don’t know exactly what the user was trying to type. I.e. Was the swipe detection wrong, or did the user delete the word because they changed their mind on what to write?
The issue isn’t a big deal for the average user. The vulnerability required them to first get your username and password, physically steal your Yubikey, spend half a day using $10-15k worth of electronics equipment to repeatedly authenticate over and over, they then could potentially make a clone of the key.
When I migrated emails last time, I setup my old email to automatically forward to the new email. Then on my new email, I setup an automatic label for any email that was addressed to the old address. Every week or two I’d review what was sent to it and either update the email address used or unsubscribe. Eventually it got to a level where I wasn’t getting much at the old email anymore and finally deleted it.
The UnifiedPush server is intended to be a single source your phone can keep a persistent connection open to, rather than needing a connection per service/app (this is how Google’s Firebase notifications work too).
As Signal doesn’t support UnifiedPush, MollySocket keeps a permanent connection open to Signal’s servers to listen for new activity and forward them to your UnifiedPush server. This saves your phone keeping a permanent connection open to Signal’s servers and draining your mobile battery more.