Dynamic Data Masking is a new security feature introduced in SQL Server 2016 that limits the access of unauthorized users to sensitive data at the database layer.

As an example of the need for such a feature is allowing the applications developers to access production data for troubleshooting purposes and preventing them from accessing the sensitive data at the same time, without affecting their troubleshooting process. Another example is the call center employee who will access the customer’s information to help him in his request, but the critical financial data, such as the bank account number or the credit card full number, will be masked to that person.