In the present invention, data relating to principals known to a computer system is centrally stored and objects having a standardized principal application programming interface (API) for finding, managing and accessing that data is provided to applications in lieu of having the applications independently store the principal data. The present invention eliminates the need for each application to create duplicate principal data. It also ensures that principal data are consistent throughout the applications on the computer system. In addition, the present invention allows any application with objects having the principal API to manage and change the principal data making such principal data easy to update. The principal API includes methods to find principals based on an identity reference to a principal or an identity claim that uniquely identifies the principal on computer system.