1. A computer program product stored in a recordable-type storage medium having instructions embodied therein when executed by a data processing system for authenticating an access request in the data processing system, comprising: first instructions for receiving the access request, wherein the access request includes a group identifier and designates a resource to which access is requested; second instructions for retrieving a complex group data object associated with the resource, wherein the complex group data object includes a group set value representing a plurality of requestor groups and a mask value, wherein the mask value masks out bits in the group identifier; and third instructions for authenticating the access request based on the group identifier, group set value and mask value, wherein the third instructions for authenticating the request based on the group identifier, group set value, and mask value include: instructions for applying the mask value to the group identifier to generate a masked group identifier; and instructions for comparing the masked group identifier to the group set value; wherein the instructions for comparing the masked group identifier to the group set value include: instructions for applying the mask value to the group set value to generate a masked group set value and instructions for comparing the masked group identifier to the masked group set value; if the masked group identifier matches the masked group set value, then the access request is authorized; if the masked group identifier does not match the masked group set value, then the access request is denied.