A person authentication system for authenticating core person data to a plurality of unrelated database systems and virtually linking the plurality of unrelated database systems thus creating a person data repository is provided. A controller module is connected to the person data repository for applying business rules to the input and modification of the core person data. An access control module connected between a user interface of any one of the plurality of unrelated databases systems and the controller module monitors for the input, query or modification of core person data and imposes the business rules on any input, query or modification of the core person data. An authentication module connected to the controller module authenticates as unique the addition of a person to the person data repository.