I live in Norway, which has a similar system, so I can’t answer for op, but the answer here is, no. Your “social security number” is not ever used as a password or other form of presumably secret key. While you probably don’t go blabbing it everywhere, there’s not much you can do if you know mine. You would also have to physically steal my phone and also learn my secret pin, or break into my fire safe in order to successfully use my personal number for anything. Address and phone number are the same thing, that’s just where you mail things to, it’s not used as a secret key.
I live in France and while we do not have public records (or just a very few), we do not have identifiers that can be easily used to do something nefarious. Our social security number, or the tax one is not used anywhere as a secure identifier (as opposed to, say, US with their SS# that is tragically comical).
We do like secrecy, though, and opening up the tax reports and addresses would be a 12 on the Richter scale of earthquakes. I do not know whether that would be good or bad but it would lead to all sorts of social unrest.
No, instead they use this radical method called actually identifying the person they're about to give a bunch of cash to instead of trying to pretend a username is a password.
