Hello everyone. In my project I have the following problem: I need to check if the CPF of a user that is registering already exists in firestore , but, for security reasons, I have defined that the user can only access the users collection (where defined the CPFs) if logged in. So I thought of some solutions:
uid (to make it easier to remove the data if the user deletes your account) and there are the CPFs. cloud function that checks the authenticity of a value, letting the user pass the collection and the field to search for .. Which of the options seems to be the most ideal? I also accept new ideas.