Interesting, will have to read up on how that works in Brazil. We also have a separate tax id here ( which is also used for pension and social security ), but that one is even more secure/private than the passport ID. We only provide that to our chosen medical insurance provider ( bc they need to register it with the ministry of finance ) as well as employers ( because 50% of the insurance has to be paid by employers).

It's explicitly not allowed and intended for generic identification purposes, because it makes it too accessible for identity theft and associated scams.