A data processing system having memory stores data elements, and includes an access control system that controls user access to the stored data elements using security label components. Each stored data element is associated with a set of data security label components, and each user is associated with a set of user security label components. The access control system receives a user request to access the stored data elements, compares the set of user security label components to the set of data security label components associated with the users, and based on the comparison result, determines whether or not to permit access to the stored data.