Comment by shp0ngle
2 years ago
This is the interesting part. For me.
> Note that if provided with the plaintext of a username known to be in use, Signal can connect that username to the Signal account that the username is currently associated with. However, once a username has been changed or deleted, it can no longer be associated with a Signal account.
The "no longer associated", I will need to get Signal word for that, right. (You cannot cryptographically prove something was deleted, right.)
But it's good enough I guess
You shouldn't need to cryptographically prove that an old username is unavailable. You should be able to simply send a request to Signal servers asking if it's available and receive "no" as a response.
You'd have to take their word that this wouldn't change, though.
Yeah but they can remember forever which real person had what username.