Designing a Verified User Status

Question

I am working on a project where I need to design the logic for the Verified user. This means that the user (based on negative feedback) cannot delete his account and start a new account under a different email identifier.

Currently, to create an account, the user enters:

 desired userID, email address (yahoo, gmail etc), Address, City, State, Zip, Phone 

How can I guarantee that the user closes his account and launches a new account so that the application can track this?

One option is to send a secure code to the user's mobile phone;

Answer 1

If they do not use the same data, you cannot. The only thing you can reliably compare is an email address, and everyone already has a few of them, and it's easy to get more.

You need to be careful if you allow only one to register an address, as this will prevent your family members from accessing your service.

Answer 2

There is no reliable way to do this, unfortunately. Unless, of course, you ask the user for the SSN, and then check it somehow.

Answer 3

Given that the combination of data that you collect is open, and its almost infinite possibilities for each value, I’m not sure that you can prevent this if each user is not tied to another device, for example, a hardware token or some other, not provided by the user out-of-band authentication hardware.